WO2021253849A1 - Procédé de précipitation de polymère - Google Patents

Procédé de précipitation de polymère Download PDF

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Publication number
WO2021253849A1
WO2021253849A1 PCT/CN2021/076466 CN2021076466W WO2021253849A1 WO 2021253849 A1 WO2021253849 A1 WO 2021253849A1 CN 2021076466 W CN2021076466 W CN 2021076466W WO 2021253849 A1 WO2021253849 A1 WO 2021253849A1
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WIPO (PCT)
Prior art keywords
acid
less
group
polymer
containing monomer
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PCT/CN2021/076466
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English (en)
Inventor
Kam Piu Ho
Yingkai JIANG
Yangjian DONG
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Guangdong Haozhi Technology Co. Limited
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Priority claimed from PCT/CN2020/096672 external-priority patent/WO2021253302A1/fr
Priority claimed from PCT/CN2020/117789 external-priority patent/WO2021253675A1/fr
Priority claimed from PCT/CN2020/139555 external-priority patent/WO2021253787A1/fr
Priority to AU2021291911A priority Critical patent/AU2021291911A1/en
Priority to CA3183237A priority patent/CA3183237A1/fr
Priority to EP21825136.1A priority patent/EP4169095A4/fr
Priority to KR1020237001858A priority patent/KR20230028398A/ko
Priority to US17/914,367 priority patent/US20230105056A1/en
Priority to CN202180007279.4A priority patent/CN114846654B/zh
Priority to JP2022578586A priority patent/JP2023530012A/ja
Application filed by Guangdong Haozhi Technology Co. Limited filed Critical Guangdong Haozhi Technology Co. Limited
Priority to US18/007,753 priority patent/US20230299372A1/en
Priority to CA3183241A priority patent/CA3183241A1/fr
Priority to JP2022577316A priority patent/JP2023529986A/ja
Priority to AU2021290702A priority patent/AU2021290702A1/en
Priority to CN202180041284.7A priority patent/CN115885408A/zh
Priority to TW110121970A priority patent/TW202210530A/zh
Priority to EP21826301.0A priority patent/EP4169109A4/fr
Priority to PCT/CN2021/100365 priority patent/WO2021254393A1/fr
Priority to KR1020237002049A priority patent/KR20230027207A/ko
Priority to TW110122185A priority patent/TW202220271A/zh
Publication of WO2021253849A1 publication Critical patent/WO2021253849A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/04—Acids; Metal salts or ammonium salts thereof
    • C08F220/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
    • C09D133/04—Homopolymers or copolymers of esters
    • C09D133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09D133/062—Copolymers with monomers not covered by C09D133/06
    • C09D133/064—Copolymers with monomers not covered by C09D133/06 containing anhydride, COOH or COOM groups, with M being metal or onium-cation
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
    • C09D133/18—Homopolymers or copolymers of nitriles
    • C09D133/22—Homopolymers or copolymers of nitriles containing four or more carbon atoms
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to the field of methods of materials recycling.
  • this invention relates to a method of precipitation of a polymer.
  • Recycling being a key component in waste reduction hierarchy, aims to recover invaluable materials from waste for reuse. Recycling of materials brings about conservation of natural resources, reduction in energy consumption (and hence, production costs) associated with extraction of raw materials and alleviates environmental impacts by reducing greenhouse gases and SO x emissions. Owing to the substantial benefits that materials recycling has to offer, developing highly efficacious and efficient methods to recycle materials is of utmost importance in achieving a circular economy.
  • Polymerization offers a powerful and modular strategy in generating macromolecules with highly complex structures and versatile functionalities. Accordingly, polymers are useful for a diverse range of applications. They have been utilized as catalysts, paints and varnishes, protective coatings, dispersants, emulsifiers, surfactants, lubricants, flocculants, thickeners, delivery agents, adhesives, insulators, packaging materials, biomaterials, construction materials, photosensitive materials, etc.
  • separation of polymers contained within the products is a technique that is heavily involved in materials recycling.
  • agent (s) could be incorporated into the polymer-containing mixture to enable polymer recovery.
  • agent (s) responsible for reacting with or inducing changes to the polymer that gives rise to the separation of the polymer from the mixture might also undergo (es) undesirable chemical reaction (s) with other constituents within the mixture which could either cause irreversible chemical changes to other constituents or allow the other constituents to similarly be extracted out from the mixture.
  • the former would make the retrieval of the other constituents in the mixture impossible and the latter would cause an ineffective separation of the polymer which not only brings about undesirable retrieval loss of other constituents in the mixture, but also a reclaimed polymer with high levels of impurities that requires subsequent purification processes.
  • separation of the polymer from the remaining mixture might be highly inefficient, taking up to several hours.
  • the method of the present invention is intended for attaining the separation of an aqueous polymer from an aqueous solvent.
  • Aqueous polymers that are known to be water-soluble and thus could be processed in aqueous media, exhibit superior dispersion and stability in water. The ability for the polymer to be uniformly distributed in water greatly enhances the specific functional performance of the polymer.
  • the well-dispersed polymer within the aqueous media poses an additional challenge in the separation of the water-soluble polymers from their respective aqueous solvents in the subsequent recycling stage.
  • PVDF polyvinylidene fluoride
  • NMP N-methyl-2-pyrrolidone
  • aqueous polymers that utilizes less expensive and more environmentally-friendly solvents, such as aqueous solvents, most commonly water, is preferred since the use of aqueous polymer can reduce the large capital cost of the recovery system.
  • the present invention details a method of precipitation of a water-soluble polymer.
  • Separation of a polymer from the mixture is initiated by the bond disruption and/or breakage between the polymer and the solvent comprised within the mixture.
  • the method or agent of choice added into the mixture should be highly specific in achieving separation of the targeted polymer without imparting unwanted chemical and physical changes on other constituents within the mixture.
  • KR Patent Application Publication No. 20030068867 A discloses a method of introducing supercritical fluid such as carbon dioxide (CO 2 ) to a polymer solution to separate the polymer from the polymer solution under supercritical conditions; wherein the polymer solution comprises polymer derived from olefin monomer (s) , olefin monomer (s) and an alkyl or benzyl-based solvent.
  • the polymer solution is first subjected to an elevation in pressure (above 500 bar, far beyond the critical pressure of CO 2 ) at constant temperature of 20 to 70 °C with the introduction of carbon dioxide to the polymer solution in forming a homogeneous solution.
  • the liquid CO 2 within the polymer solution could then act as an anti-solvent to precipitate the polymer.
  • the precipitated polymer is removed from the remaining polymer solution by lowering the pressure of the remaining solution to vaporize the CO 2 , solvent and monomers.
  • an extremely high pressure well beyond the atmospheric pressure, is required for the involved process in order to initiate the precipitation of the polymer. This method would in turn generate substantial energy costs (which stems from the high energy consumption) in the separation process.
  • high-pressure processing is likely to present safety concerns.
  • the present invention sets forth a method of precipitation of a polymer in accomplishing complete separation of the polymer from the mixture via the use of a precipitation agent. Furthermore, the method disclosed herein is specifically developed for the optimization of the polymer formulation. The method for precipitation of a polymer disclosed herein is developed to initiate the bond disruption and/or breakage between the polymer and the aqueous solvent within the mixture.
  • the precipitation phenomenon relates to a phase-conversion reaction where the polymer in the liquid phase is rapidly converted into solid phase.
  • the polymer comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • a precipitation method of the present invention that fulfills these qualities in promoting changes to the interactions between the polymer and the aqueous solvent is highly applicable to retrieve a polymer from a mixture. It would circumvent both complex separation process and contamination of the polymer, enables excellent materials recovery and allows the precipitation of the polymer to be achieved within a short time frame.
  • a method for precipitating a polymer by adding a precipitation agent into a first suspension to form a second suspension; wherein the first suspension comprises a polymer and an aqueous solvent; and wherein the polymer comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • the precipitation agent is an acid.
  • the acid is a strong acid, a weak acid or a combination thereof.
  • the strong acid is selected from the group consisting of nitric acid, sulphuric acid, hydrochloric acid, perchloric acid, hydrobromic acid, hydroiodic acid, chloric acid, bromic acid, iodic acid, dithionic acid, dithionous acid, sulfamic acid, trithionic acid, tetrathionic acid, methane sulphonic acid, p-toluenesulfonic acid, benzene sulfonic acid, trichloroacetic acid, trifluoroacetic acid, oxalic acid, propiolic acid, mesoxalic acid, mellitic acid or combinations thereof.
  • the pK a of the strong acid is from about -10 to about 2. In some embodiments, the pK a of the strong acid is between -10 and 2.
  • the weak acid is selected from the group consisting of formic acid, acetic acid, glycolic acid, glyoxylic acid, oxalic acid, propionic acid, acrylic acid, lactic acid, 3-hydroxipropionic acid, glyceric acid, pyruvic acid, 3-oxopropionic acid, 2, 3-dioxopropionic acid, malonic acid, tartronic acid, dihydroxymalonic acid, mesoxalic acid, glycidic acid, butyric acid, isobutyric acid, crotonic acid, isocrotonic acid, methacrylic acid, vinylacetic acid, tetrolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-oxobutanoic acid, acetoacetic acid, 4-oxobutanoic acid, butanedioic acid, methylmalonic acid, fumaric acid, maleic acid, 2-hydroxybutanedioic acid, tartaric
  • the pH of the second suspension is from about 0.2 to about 4.5.
  • the precipitation of a polymer attained using the method provided herein is straightforward, occurs within a short period of time and does not incur a penalty in terms of suffering from recovery loss of the polymer and other constituents in the first suspension, damaging and introducing impurities to the retrieved polymer.
  • the aforementioned method is employed as part of the recycling process of battery electrode to attain separation of a polymeric binder from the remaining of the second suspension, wherein the polymeric binder is a polymer.
  • a method for precipitating a polymeric binder by adding a precipitation agent into the first suspension to form a second suspension; wherein the first suspension comprises an electrode layer and an aqueous solvent; wherein the electrode layer comprises a polymeric binder; and wherein the polymeric binder comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • the simple utilization of a precipitation agent in the present invention to precipitate a polymer from a second suspension can help achieve complete separation of the polymer from the remaining of the second suspension, reduce the time taken for precipitation of the polymer, maximize invaluable materials recovery, eliminate contamination of polymer and/or other constituents in the second suspension and prevent the need for subsequent downstream processing.
  • the method disclosed herein is found to be applicable to precipitate a polymeric binder within a battery electrode without inducing undesirable chemical changes and phase transitions to other constituents such as the electrode active materials within the second suspension.
  • Figure 1 illustrates a schematic of an embodiment of the proposed interactions between a polymer and an aqueous solvent in a first suspension.
  • Figure 2 illustrates a schematic of an embodiment of the proposed alterations in interactions between a polymer and an aqueous solvent as sufficient concentration of precipitation agent is added into the first suspension.
  • Figures 3A and 3B depict an embodiment of the structural conformations of a polymer before and after the addition of a precipitation agent into a first suspension respectively.
  • Figure 4 illustrates a schematic of an embodiment of the proposed alterations in interactions between a polymer and an aqueous solvent as insufficient concentration of precipitation agent is added into the first suspension.
  • Figure 5 illustrates a schematic of an embodiment of the proposed alterations in interactions between a polymer which comprises a copolymer comprising structural unit (s) derived from one or more carboxylic acid group-containing monomer (s) and an aqueous solvent as sufficient concentration of precipitation agent is added into the first suspension.
  • Figures 6A and 6B depict the physical conditions of second suspensions of Comparative Example 1 and Example 2 with a pH of 6 and 3 respectively after the addition of a precipitation agent into a first suspension in forming the second suspensions.
  • Figures 7A and 7B illustrate the infrared spectroscopy of the precipitated polymer and the remaining of the second suspension of Example 38 respectively.
  • Figures 8A and 8B illustrate the infrared spectroscopy of the precipitated polymer and the remaining of the second suspension of Example 37 respectively.
  • Figure 9 is a flow chart of an embodiment illustrating the steps for precipitating a polymer as disclosed herein and its subsequent further processing for extraction of the precipitated polymer.
  • Figure 10 is a flow chart of an embodiment illustrating the steps for precipitating an polymeric binder as disclosed herein and its subsequent further processing for extraction of the precipitated polymer.
  • a method for precipitating a polymer by adding a precipitation agent into a first suspension to form a second suspension; wherein the first suspension comprises a polymer and an aqueous solvent; and wherein the polymer comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • the method of the present invention is used as part of a battery electrode recycling regime.
  • a method for precipitating a polymeric binder by adding a precipitation agent into a first suspension to form a second suspension; the first suspension comprises an electrode layer and an aqueous solvent; wherein the electrode layer comprises a polymeric binder; and wherein the polymeric binder comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • Electrode refers to a “cathode” or an “anode. ”
  • positive electrode is used interchangeably with cathode.
  • negative electrode is used interchangeably with anode.
  • polymeric binder refers to a chemical compound, mixture of compounds, or polymer that is used to hold material (s) in place.
  • the polymeric binder is used to adhere material (s) onto a substrate to form a composite.
  • the substrate is a conductive metal.
  • the substrate is a non-conductive metal.
  • the polymeric binder refers to a chemical compound, mixture of compounds, or polymer that is used to hold an electrode material and/or a conductive agent in place and adhere them onto a conductive metal part to form an electrode.
  • the electrode does not comprise any conductive agent.
  • the polymeric binder forms a colloid, solution or dispersion in an aqueous solvent such as water.
  • conductive agent refers to a material that has good electrical conductivity. Therefore, the conductive agent is often mixed with an electrode active material at the time of forming an electrode to improve electrical conductivity of the electrode.
  • the conductive agent is chemically active. In some, the conductive agent is chemically inactive.
  • polymer refers to a compound prepared by polymerizing monomers, whether of the same or a different type.
  • the generic term “polymer” embraces the terms “homopolymer” as well as “copolymer” .
  • homopolymer refers to a polymer prepared by the polymerization of the same type of monomer.
  • a coiled polymer chain refers to a linear or an almost linear configuration of a polymer chain.
  • a coiled polymer chain comprises like charges along the chain which repel each other.
  • copolymer refers to a polymer prepared by the polymerization of two or more different types of monomers.
  • unsaturated refers to a moiety having one or more units of unsaturation.
  • alkyl or “alkyl group” refers to a univalent group having the general formula C n H 2n+1 derived from removing a hydrogen atom from a saturated, unbranched or branched aliphatic hydrocarbon, where n is an integer, or an integer between 1 and 20, or between 1 and 8.
  • alkyl groups include, but are not limited to, (C 1 –C 8 ) alkyl groups, such as methyl, ethyl, propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2, 2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2, 2-dimethyl-1-butyl, 3, 3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, isobutyl, t–butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl and octyl.
  • C 1 –C 8 alkyl groups such as
  • Longer alkyl groups include nonyl and decyl groups.
  • An alkyl group can be unsubstituted or substituted with one or more suitable substituents.
  • the alkyl group can be branched or unbranched. In some embodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.
  • cycloalkyl refers to a saturated or unsaturated cyclic non-aromatic hydrocarbon radical having a single ring or multiple condensed rings.
  • cycloalkyl groups include, but are not limited to, (C 3 -C 7 ) cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, and saturated cyclic and bicyclic terpenes and (C 3 -C 7 ) cycloalkenyl groups, such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and cycloheptenyl, and unsaturated cyclic and bicyclic terpenes.
  • a cycloalkyl group can be unsubstituted or substituted by one or two suitable substituents. Furthermore, the cycloalkyl group can be monocyclic or polycyclic. In some embodiments, the cycloalkyl group contains at least 5, 6, 7, 8, 9, or 10 carbon atoms.
  • alkoxy refers to an alkyl group, as previously defined, attached to the principal carbon chain through an oxygen atom.
  • Some non-limiting examples of the alkoxy group include methoxy, ethoxy, propoxy, butoxy, and the like.
  • the alkoxy defined above may be substituted or unsubstituted, wherein the substituent may be, but is not limited to, deuterium, hydroxy, amino, halo, cyano, alkoxy, alkyl, alkenyl, alkynyl, mercapto, nitro, and the like.
  • alkenyl refers to an unsaturated straight chain, branched chain, or cyclic hydrocarbon radical that contains one or more carbon-carbon double bonds.
  • alkenyl groups include, but are not limited to, ethenyl, 1-propenyl, or 2-propenyl, which may optionally be substituted on one or more of the carbon atoms of the radical.
  • aryl refers to an organic radical derived from a monocyclic or polycyclic aromatic hydrocarbon by removing a hydrogen atom.
  • Non-limiting examples of the aryl group include phenyl, naphthyl, benzyl, or tolanyl group, sexiphenylene, phenanthrenyl, anthracenyl, coronenyl, and tolanylphenyl.
  • An aryl group can be unsubstituted or substituted with one or more suitable substituents.
  • the aryl group can be monocyclic or polycyclic. In some embodiments, the aryl group contains at least 6, 7, 8, 9, or 10 carbon atoms.
  • aliphatic refers to a C 1 to C 30 alkyl group, a C 2 to C 30 alkenyl group, a C 2 to C 30 alkynyl group, a C 1 to C 30 alkylene group, a C 2 to C 30 alkenylene group, or a C 2 to C 30 alkynylene group.
  • the alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.
  • aromatic refers to groups comprising aromatic hydrocarbon rings, optionally including heteroatoms or substituents.
  • groups include, but are not limited to, phenyl, tolyl, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, triphenylenyl, and derivatives thereof.
  • substituted refers to that at least one hydrogen atom of that compound or chemical moiety is replaced with a second chemical moiety.
  • substituents include, but are not limited to, halogen; alkyl; heteroalkyl; alkenyl; alkynyl; aryl, heteroaryl, hydroxyl; alkoxyl; amino; nitro; thiol; thioether; imine; cyano; amido; phosphonato; phosphine; carboxyl; thiocarbonyl; sulfonyl; sulfonamide; acyl; formyl; acyloxy; alkoxycarbonyl; oxo; haloalkyl (e.g., trifluoromethyl) ; carbocyclic cycloalkyl, which can be monocyclic or fused or non-fused polycyclic (e.g., cyclopropyl, cyclobuty
  • olefin refers to an unsaturated hydrocarbon-based compound with at least one carbon-carbon double bond.
  • halogen or “halo” refers to F, Cl, Br or I.
  • monomeric unit refers to the constitutional unit contributed by a single monomer to the structure of a polymer.
  • structural unit refers to the total monomeric units contributed by the same monomer type in a polymer.
  • the term “acid salt group” refers to the acid salt formed when an acid reacts with a base or when an acid dissociates in an aqueous solvent such as water.
  • the proton of the acid is replaced with a metal cation.
  • the proton of the acid is replaced with an ammonium ion.
  • polyatomic refers to an electrically neutral group of three of more atoms held together by covalent bonds.
  • polyprotic acid refers to an acid having two or more ionizable hydrogen ions (i.e. protons) per molecule.
  • hydrophilic refers to a tendency to dissolve in or interact with polar solvents, especially water, or polar functional groups. Hydrophilic groups are usually themselves polar, and in many cases, such hydrophilic groups are able to form hydrogen bonds with water molecules. Some non-limiting hydrophilic groups include acid, hydroxyl, and amide.
  • hydrophobic group refers to a functional group that tends not to dissolve or interact with polar solvents, especially water, or polar functional groups. Hydrophobic groups are usually non-polar.
  • number average molecular weight (M n ) of a polymer is defined mathematically as:
  • N i is the number of polymer molecules with a particular molecular weight M i .
  • weight average molecular weight (M w ) of a polymer is defined mathematically as:
  • N i is the number of polymer molecules with a particular molecular weight M i .
  • polydispersity index refers to a ratio of the weight average molecular weight (M w ) relative to the number average molecular weight (M n ) . It is a measure of the distribution of the molecular weight within a given polymer sample.
  • planetary mixer refers to an equipment that can be used to mix or stir different materials for producing a homogeneous mixture, which consists of blades conducting a planetary motion within a vessel.
  • the planetary mixer comprises at least one planetary blade and at least one high-speed dispersion blade.
  • the planetary and the high-speed dispersion blades rotate on their own axes and also rotate continuously around the vessel.
  • the rotation speed can be expressed in unit of rotations per minute (rpm) which refers to the number of rotations that a rotating body completes in one minute.
  • ultrasonicator refers to an equipment that can apply ultrasound energy to agitate particles in a sample. Any ultrasonicator that can disperse the mixture, suspension, solution or slurry disclosed herein can be used herein. Some non-limiting examples of the ultrasonicator include an ultrasonic bath, a probe-type ultrasonicator, and an ultrasonic flow cell.
  • ultrasonic bath refers to an apparatus through which the ultrasonic energy is transmitted via the container’s wall of the ultrasonic bath into the liquid sample.
  • probe-type ultrasonicator refers to an ultrasonic probe immersed into a medium for direct sonication.
  • direct sonication means that the ultrasound is directly coupled into the processing liquid.
  • ultrasonic flow cell or “ultrasonic reactor chamber” refers to an apparatus through which sonication processes can be carried out in a flow-through mode.
  • the ultrasonic flow cell is in a single-pass, multiple-pass or recirculating configuration.
  • applying refers to an act of laying or spreading a substance on a surface.
  • the term “current collector” refers to any conductive substrate, which is in contact with an electrode layer and is capable of conducting an electrical current flowing to electrodes during discharging or charging a secondary battery.
  • the current collector include a single conductive metal layer or substrate and a single conductive metal layer or substrate with an overlying conductive coating layer, such as a carbon black-based coating layer.
  • the conductive metal layer or substrate may be in the form of a foil or a porous body having a three-dimensional network structure, and may be a polymeric or metallic material or a metalized polymer. In some embodiments, the three-dimensional porous current collector is covered with a conformal carbon layer.
  • electrode layer refers to a layer, which is in contact with a current collector, that comprises an electrochemically active material.
  • the electrode layer is made by applying a coating on to the current collector.
  • the electrode layer is located on one side or both sides of the current collector.
  • the three-dimensional porous current collector is coated conformally with an electrode layer.
  • room temperature refers to indoor temperatures from about 18 °C to about 30 °C, e.g., 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 °C. In some embodiments, room temperature refers to a temperature of about 20 °C +/-1 °C or +/-2 °C or +/-3 °C. In other embodiments, room temperature refers to a temperature of about 22 °C or about 25 °C.
  • solid content refers to the amount of non-volatile material remaining after evaporation.
  • peeling strength refers to the amount of force required to separate a current collector and an electrode layer that are bonded to each other. It is a measure of the binding strength between such two materials and is usually expressed in N/cm.
  • adheresive strength refers to the amount of force required to separate a current collector and a polymeric binder coating that are bonded to each other. It is a measure of the binding strength between such two materials and is usually expressed in N/cm.
  • water-soluble refers to the capability of a substance in dissolving in water with trace amounts or none of the materials remained undissolved in water.
  • water-soluble embraces the terms “entirely water-soluble” , “mostly water-soluble” and “slightly water-insoluble” .
  • the method of the present invention has been developed that is uniquely tailored for the specific need of extracting a polymer from a first suspension, wherein the first suspension comprises a polymer and an aqueous solvent.
  • the polymer is water-soluble and utilizes aqueous solvents, most commonly water, which forms the basis for the making of a water-based solution.
  • the polymers are capable of achieving good dispersion and stability in water, which can appreciably boost the functional performance of the polymers. For example, in the case where the polymer is a polymeric binder, the adhesive strength of a well-dispersed polymeric binder in water considerably increases, and thus brings about an enhancement in the binding capability of the polymeric binder.
  • the polymer of the present invention is capable of dissolving and/or dispersing into an aqueous solvent in forming the first suspension in the first place.
  • the dissolution of a polymer in an aqueous solvent in forming a first suspension is driven by the (1) intermolecular interactions (e.g. hydrogen bonding and ion-dipole interactions) between the polymer and the aqueous solvent, or more specifically between the ionized and/or uncharged species in the monomer (s) that contribute (s) to the make-up of the polymer and the polar molecules comprised within the aqueous solvent; and (2) uncoupling of a proportion of interactions between the water molecules in the aqueous solvent, occurred especially in regions that are in close proximity to the polymer.
  • intermolecular interactions e.g. hydrogen bonding and ion-dipole interactions
  • Hydrogen bonding among the polymer and the aqueous solvent depends on the ability of each to form hydrogen bond (i.e. accept and/or donate hydrogen bond) .
  • the polymer comprises a copolymer.
  • the copolymer comprises a structural unit (a) derived from an acid group-containing monomer and a structural unit (b) derived from a nitrile group-containing monomer.
  • the copolymer comprises a structural unit (a) derived from an acid group-containing monomer, a structural unit (b) derived from a nitrile group-containing monomer, a structural unit (c) derived from an amide group-containing monomer or combinations thereof.
  • the copolymer further comprises a structural unit (d) derived from a hydroxyl group-containing monomer, a structural unit (e) derived from an ester group-containing monomer, a structural unit (f) derived from an epoxy group-containing monomer, a structural unit (g) derived from a fluorine-containing monomer or combinations thereof.
  • each of the above-mentioned monomers that can potentially constitute the make-up of the copolymer independently consists of either a strongly electronegative atom, particularly nitrogen (N) , oxygen (O) or fluorine (F) atom (known as a hydrogen bond donor, Dn) that is covalently bonded to a hydrogen (H) atom or another electronegative atom bearing a lone pair of electrons in the outermost electron shell of the atom (known as a hydrogen bond acceptor, Ac) .
  • a hydrogen bond donor atom
  • H hydrogen
  • Ac hydrogen bond acceptor
  • Dn is a hydrogen bond donor
  • Ac is a hydrogen bond acceptor
  • the solid line denotes a polar covalent bond and the dotted line indicates a hydrogen bond.
  • structural unit (a) derived from an acid group-containing monomer comprises an acid salt group.
  • an acid salt group is a salt of an acid group.
  • the anion of the acid salt group is capable of forming ion-dipole interactions with a partially positively charged species (for example a partial positive charge near the hydrogen atom of a water molecule, which stems from the uneven distribution of electron density in the water molecule) .
  • structural unit (a) comprises an alkali metal acid salt group. Examples of an alkali metal forming the alkali metal acid salt include lithium, sodium and potassium.
  • structural unit (a) comprises an ammonium acid salt group.
  • the aqueous solvent is a solution containing water as the major component and a volatile solvent, such as alcohols, lower aliphatic ketones, lower alkyl acetates or the like, as the minor component in addition to water.
  • the aqueous solvent consists solely of water.
  • the hydroxyl groups of water consist of a H atom covalently bonded to a more electronegative O atom and an electronegative O atom bearing a lone pair of electrons in the outmost electron shell, either of which is capable of forming hydrogen bond with another species (e.g. a monomer that assists in the construction of the polymer) that can interact via hydrogen bonding (i.e. molecule containing (i) a H atom which is covalently bonded to a hydrogen bond donor and/or (ii) a hydrogen bond acceptor) .
  • the ability of water in both accepting and donating hydrogen bonds makes it an excellent candidate in solvating a polymer.
  • the aqueous solvent comprises a minor component in addition to water that possesses hydrogen bond-forming capability
  • hydrogen bond interactions could also be established between the minor component and another hydrogen bond-forming molecule (e.g. a hydrogen bond-forming group of a monomer that contributes the make-up of the polymer) .
  • the polarity of the aqueous solvent constituents is yet another most important factor in governing how well the aqueous solvent solvates the polymer.
  • a polar molecule contains at least one polar bond formed due to the difference in electronegativities between the bonded atoms. As the electron pair (s) shared between the bonded atoms tend to be drawn closer to the atom with a higher electronegativity, an uneven distribution of the bonding electron pair (s) occurs. The more electronegative atom obtains a partial negative charge whereas the less electronegative atom has a partial positive charge. A bond dipole moment arises with this separation of positive and negative charges.
  • the dipole moment of the molecule is the vector sum of all bond dipole moments present in the molecule.
  • a polar molecule with two or more polar bonds has a net dipole as a result of opposing charges from polar bonds arranged asymmetrically in at least one direction, so that the bond dipole moments do not cancel each other.
  • a water molecule for example, is a polar molecule since the bond dipole moments present in the molecule do not cancel out, resulting in a net dipole.
  • the polar molecules within the aqueous solvent solvate a charged species in the polymer (e.g. an anion of the acid salt group of a monomer that assists in the construction of the polymer) by orientating the appropriate partially charged portion of the molecules towards the charged species through electrostatic attraction.
  • a charged species in the polymer e.g. an anion of the acid salt group of a monomer that assists in the construction of the polymer
  • Hydrogen bonding and/or ion-dipole attractions are the two types of interactions primarily formed between the polymer and the aqueous solvent that bring about the formation of solvation complexes. Both of which independently contribute to a different extent to the dissolution of polymer depending on the molecular structure, composition and properties of the polymer and the aqueous solvent. Solvation of the polymer in the aqueous solvent could proceed through other means of intermolecular interactions, for instance via ionic interactions, London dispersion forces, dipole-dipole interactions, dipole-induced dipole interactions and ion-induced dipole interactions.
  • the principal electrostatic interactions that give rise to solvation of the polymer by the aqueous solvent occur via hydrogen bonding and/or ion-dipole interactions.
  • the other interactions mentioned above that could possibly arise to a less extent between the polymer and the aqueous solvent may also be disrupted based on the proposed mechanism via the introduction of the precipitation agent to allow for the precipitation of the polymer. These interactions are not displayed for ease of interpretation.
  • Figure 1 illustrates a schematic of an embodiment of the proposed interactions between a polymer and an aqueous solvent in a first suspension.
  • the polymer compound in bold represents an embodiment of the polymer comprises a copolymer comprising structural units derived from a carboxylic acid group-containing monomer, a nitrile group-containing monomer and an amide group-containing monomer.
  • the structural unit (s) derived from a carboxylic acid group-containing monomer in this case comprises a carboxylic salt group, wherein a carboxylic salt group is a salt of a carboxylic acid group.
  • the aqueous solvent in this case comprises water.
  • Oxygen (O) , nitrogen (N) and hydrogen (H) atoms present in the copolymer of polymer are likely to interact with the O and/or H atoms of the water molecules in the aqueous solvent via hydrogen bond formations.
  • an ion-dipole interaction is exerted between the anion of the carboxylic salt group, COO - in this case, contained within polymer and the partial positive charge near the hydrogen atom of a water molecule in the aqueous solvent.
  • Hydrogen bonding and/or ion-dipole attractions are the two types of interactions primarily formed between the polymer and the aqueous solvent in a first suspension and thus independently contribute considerably to the solvation and dissolution of the polymer by the aqueous solvent in forming a first suspension.
  • hydrogen bonds initially formed between the water molecules within the aqueous solvent that are in close proximity to the polymer i.e. at the inner solvation shells around the polymer
  • hydrogen bonding between water molecules that are further away from the polymer i.e. at the outer solvation shells around the polymer persists with considerably less disruption exerted from interactions between the polymer and the aqueous solvent on these molecules.
  • the ability for the polymer to dissolve in water and uniformly distributed among the water molecules is found to substantially improve the specific functional performance of the polymer.
  • the polymer disclosed herein is devised to possess such capabilities in its dissolution and exceptional dispersion in an aqueous solvent through the hydrogen bonding and/or ion-dipole interactions between the polymer and the aqueous solvent.
  • the formulation of the polymer disclosed herein could be utilized as a polymeric binder to provide an exceptionally strong binding capability for various applications.
  • the copolymer of the polymer comprises a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • the polymer could be used for other purposes other than as a polymeric binder.
  • the dissolved and well-dispersed polymer within the first suspension poses an additional challenge in the separation of the water-soluble polymers from their respective first suspensions in the subsequent recycling stage as the polymer-containing product reaches its end of its lifespan or as the product rejects are generated during production.
  • Copolymers in polymers of different compositions that display varying specific properties would require different approaches in extraction by first disrupting the initially-formed solvation complexes to allow for the detachment of the copolymer from the aqueous solvent.
  • the method of the present invention is specifically developed to precipitate a polymer from a first suspension. More specifically, the method of the present invention is developed to precipitate a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer from a first suspension.
  • the copolymer further comprises a structural unit derived from a hydrogen bond-forming group-containing monomer.
  • the hydrogen bond-forming group-containing monomer may be an amide group-containing monomer, a hydroxyl group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine-containing monomer or combinations thereof.
  • the precipitation of a polymer disclosed herein is driven by two main events: (1) the various types of interactions that bring about the separation of the polymer from the aqueous solvent and (2) the subsequent structural transformation of the polymer.
  • the polymer Upon addition of a precipitation agent, the polymer is separated from the aqueous solvent in a first suspension via (i) bond disruption and/or breakage between the copolymer of polymer and the aqueous solvent; (ii) weakening of intermolecular attractions between molecules in the aqueous solvent in forming solvation complex; (iii) protonation of conjugate base of the acid group-containing monomer (s) that contribute the make-up of the polymer; (iv) formation of intramolecular interactions between various functional groups within a copolymer chain and (v) development of intermolecular interactions between the copolymer chains.
  • the present invention provides a method for precipitating a polymer by adding a precipitation agent into the first suspension to form a second suspension; wherein the first suspension comprises a polymer and an aqueous solvent; and wherein the polymer comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • the precipitation agent is an acid. In some embodiments, the precipitation agent is a strong acid.
  • Acid strength refers to the tendency of an acid to dissociate in a solvent (most commonly water) into a proton and a conjugate base of the acid.
  • the extent of ionization of an acid is usually quantified by its acid dissociation constant (K a ) .
  • Stronger acids have a larger K a and thus correspond to a smaller negative logarithm of the acid dissociation constant (pK a , which is equal to -log K a ) than weaker acids.
  • the first suspension disclosed herein comprises an aqueous solvent comprising water.
  • a strong acid into the first suspension disclosed herein in forming a second suspension, the dissociation of a strong acid in water is effectively complete with which the acid loses a proton and the water molecule takes up the proton in producing a hydroxonium ion (H 3 O + ) .
  • the said strong acid dissociation reaction is generally denoted as:
  • HA 1 is a strong acid utilized as a precipitation agent
  • H 2 O is a water molecule
  • H 3 O + is a hydroxonium ion
  • a 1 ⁇ is a conjugate base of the acid HA 1 .
  • the precipitation agent is a weak acid.
  • the weak acid With the incorporation of a weak acid into the first suspension in forming a second suspension, the weak acid only partially dissociates with both the undissociated weak acid and its dissociation products present in the second suspension.
  • the dissociation of the said weak acid is represented by the following equation:
  • HA 2 is a weak acid utilized as a precipitation agent and A 2 - is a conjugate base of the acid HA 2 .
  • the dissociation of a weak acid in the second suspension involves reaction of water molecules with protons from the acid in generating hydroxonium ions.
  • the presence of the hydroxonium ions in the second suspension regardless of being formed from the dissociation of a strong acid or a weak acid, removes the hydrogen bond-forming and ion-dipole interacting sites that are originally present in the water molecules which disrupts and breaks up the electrostatic attractions (i.e. hydrogen bonding and/or ion-dipole interactions) that were initially created between the polymer and the water molecules in the aqueous solvent. This results in the disintegration of the solvation shells that were formerly developed around the polymer, reducing the dissolution ability of the polymer in the aqueous solvent.
  • hydroxonium ions formed could protonate ionized species in the monomer (s) (e.g. the anion of an acid salt group-containing monomer) that contribute (s) to the make-up of the polymer. This might potentially promote the conversion of negatively charged species to their protonated uncharged form, as shown in the following equation:
  • HA 3 is a monomer that assists in the construction of the polymer and A 3 - is a conjugate base of the monomer HA 3 .
  • the acid salt group is transformed into an acid group.
  • the pK a value of the acid to be utilized as the precipitation agent should be lower than that of the acid group-containing monomer (s) that make up the polymer and (2) upon addition of the precipitation agent into the first suspension in forming a second suspension, the pH value of the second suspension should be sufficiently lower than the pK a value (s) of the acid group-containing monomer (s) that make up the polymer.
  • the pK a value quantifies the degree of dissociation of an acid in a solvent such as water.
  • a pK a value of the acid to be utilized as the precipitation agent lower than that of the acid group-containing monomer (s) that contribute the make-up of the polymer, the acid utilized as the precipitation agent has a stronger inclination to dissociate, shifting the equilibrium position of the reaction of Equation 2 to the right, with a higher likelihood of hydroxonium ions formed from the ionization of said acid upon contact of the acid with the first suspension.
  • the conjugate base of the acid group-containing monomer (s) is more prone to protonation, with the equilibrium position of reaction of Equation 3 lying towards the right, taking up part of the hydroxonium ions formed from the dissociation of the acid utilized as precipitation agent.
  • the acid Upon addition of acid that is utilized as precipitation agent into the first suspension, the acid undergoes dissociation in generating hydroxonium ions and leads to the formation of a second suspension. It would be highly desirable in attaining higher concentrations of hydroxonium ions in the second suspension in the present invention, which is driven by the utilization of stronger acids and/or the amount of acid as precipitation agent added to the first suspension. Presence of higher concentrations of hydroxonium ions in the second suspension not only aids the separation of the polymer from the aqueous solvent by assisting the bond disruption process, but also further shifts the equilibrium position of reaction of Equation 3 to the right and protonates the conjugate base of the acid group-containing monomer (s) that contribute to the construction of the polymer.
  • the pH of the second suspension should be sufficiently low to enable the protonation of the majority of the conjugate base of the acid group-containing monomer (s) . This could potentially eradicate the presence of charge-bearing conjugate base of the acid group-containing monomer (s) (e.g. acid salt group-containing monomer) and eliminate any further ion-dipole interactions between polymer and the aqueous solvent that are originally present in the first suspension.
  • the functional groups contained within the polymer have a higher affinity of interacting with each other.
  • the H atom of a carboxyl group in a polymer is likely to interact with the N atom of a nitrile group contained within the same polymer via hydrogen bonding interactions.
  • Dipole-dipole interactions might also be found between the O atom of a carboxyl group in the polymer and the C atom of a nitrile group in the same polymer.
  • the separation of the polymer disclosed herein from the aqueous solvent is accomplished through the involvement of the various kinds of interactions mentioned above upon addition of a precipitation agent.
  • the effect of which combined with the specific formulation of the polymer of the present invention allow for the coil-to-globule structural conformation of the polymer.
  • the polymer can then be subsequently precipitated.
  • the protonation of conjugate base of the acid group-containing monomer (s) that contribute the make-up of the polymer is highly favorable. This protonation reaction promotes a coil-to-globule structural transition of the polymer disclosed herein.
  • the negatively charged species in the monomer (s) e.g. anion (s) of an acid salt group-containing monomer
  • the negatively charged species effectively repel each other.
  • the electrostatic repulsion of the ionized group (s) leads to the expansion of the charged polymer into a fully solvated open coil conformation.
  • the protonation of the majority of the conjugate base of the acid group-containing monomer (s) that contribute the make-up of the polymer converts the formerly charged polymer to its uncharged form where electrostatic repulsion is no longer exerted. This leads to severe weakening of the intermolecular interactions (particularly ion-dipole interactions) between the structural unit derived from an acid group-containing monomer and the aqueous solvent and initiates the aggregation of the polymer.
  • the apparent intramolecular interactions between functional groups within a copolymer chain and the intermolecular interactions between the copolymer chains further promote the winding of the polymers and assist the transition of the polymers into a compact globular conformation.
  • the polymer disclosed herein comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • An acid group (e.g. a carboxylic acid group) is one of the crucial functional groups present in the polymer that is polar in nature because of the differences in electronegativities of carbon (C) atom and oxygen (O) atom in the carbonyl group and of oxygen (O) atom and hydrogen (H) atom in the hydroxyl group.
  • the atoms possess unequal charge distributions and therefore have net dipole moment, making the acid group polar in nature. This allows the acid group to participate in hydrogen bond formation and/or dipole-dipole interactions.
  • An acid group is highly hydrophilic, rendering the acid group to be extremely soluble in an aqueous solvent (e.g. water) .
  • a hydrophobic group-containing monomer is a nitrile group-containing monomer.
  • the nitrile group is polar in nature due to the strong electronegativity of the nitrogen (N) atom contained within as compared to the carbon (C) atom.
  • the electrons shared between the covalently bonded C and N are more strongly attracted towards the N atom than the C atom.
  • the N atom therefore carries a partial negative charge and the C atom carries a partial positive charge, as shown in the form of ⁇ + C ⁇ N ⁇ - .
  • the nitrogen (N) atom of a nitrile group (-C ⁇ N) has the potential to act as a proton (i.e. hydrogen ion) acceptor for hydrogen bond formation with water molecules in the aqueous solvent because of the presence of a lone-pair electron orbital.
  • a proton i.e. hydrogen ion
  • the interactions created between the nitrile groups and the water molecules are remarkably weaker than that of between the other polar groups comprising at least one of each of hydrogen bond donor and hydrogen bond acceptor per group (e.g. acid group and amide group) and the water molecules.
  • PAN polyacrylonitrile
  • hydrophobic functional group in a structural unit e.g. a structural unit derived from a nitrile group-containing monomer
  • hydrophobic group (s) contained within the polymer exerts hydrophobic tendency towards the entire copolymer of the polymer.
  • the proportion of hydrophobic group (s) contained within the polymer the extent of hydrophobicity of the polymer could be determined. With a higher proportion of hydrophobic group (s) contained within the polymer, the more hydrophobic the polymer is, and thus the more insoluble the polymer is in water.
  • the polymer disclosed herein comprising a structural unit derived from a nitrile group-containing monomer exhibiting its hydrophobic property, the polymer further collapses into a dense globular structure, driven by contact surface area minimization between the polymer and water molecules in the aqueous solvent.
  • Figure 2 illustrates a schematic of an embodiment of the proposed alterations in interactions between the polymer and the aqueous solvent outlined in Figure 1 as sufficient concentration of precipitation agent is added into the first suspension.
  • the polymer compound in bold represents an embodiment of the polymer comprises a copolymer comprising structural units derived from a carboxylic acid group-containing monomer, a nitrile group-containing monomer and an amide group-containing monomer.
  • the precipitation agent in this case comprises hydrochloric acid, which is a type of strong acid; while the aqueous solvent in this scenario comprises water.
  • hydrochloric acid As hydrochloric acid is added into the first suspension, the complete dissociation of the hydrochloric acid in water occurs. The acid loses a proton and the water molecule takes up the proton and forms a hydroxonium ion, as shown below:
  • hydroxonium ions generated from the ionization of the hydrochloric acid, eliminates most of the hydrogen bond-forming and ion-dipole interacting sites embedded in water molecules. This severely disrupts the intermolecular interactions that were originally established between the polymer and the water molecules as illustrated in Figure 1. This diminishes the extent of solvation of the polymer by the water molecules in the second suspension.
  • the hydroxonium ions formed from the dissociation of the hydrochloric acid tend to protonate anions of the carboxylic salt group-containing monomers (salts of acrylic acid and methacrylic acid in this case as illustrated in Figure 2) that contribute to the make-up of the polymer as described in Figure 1.
  • the protonation reaction of the carboxylic salt group-containing monomer is shown in Equation 5 below:
  • R 1 COOH is a carboxylic acid group-containing monomer that assists in the construction of the polymer and R 1 COO - is a conjugate base of the monomer R 1 COOH (i.e. a carboxylic salt group-containing monomer) .
  • the anions of the carboxylic salt group-containing monomer that contribute to the construction of the polymer exert an electrostatic repulsion against each other which gives a charged polymer with a fully solvated coil structure.
  • This coil-like structure of the charged polymer could be visualized in Figure 3A.
  • the carboxylic salt group-containing monomer being subjected to protonation, the negatively charged acid salt group is transformed into an uncharged acid group in the monomer which constitutes the building block of the polymer. The absence of repulsion forces within the polymer initiates the winding motion of the polymer.
  • the acid group-containing monomer that assists in the make-up of the polymer as illustrated in Figure 2 comprises an acrylic acid and a methacrylic acid.
  • Acrylic acid has a pK a value of 4.3, while the pK a value of methacrylic acid is 4.7.
  • the pK a of hydrochloric acid is -6.3. With the pK a value of hydrochloric acid (HCl) being substantially smaller than that of both acrylic acid and methacrylic acid (i.e.
  • hydrochloric acid has a much stronger inclination to dissociate in forming hydroxonium ions.
  • the strength of hydrochloric acid is extremely high that complete dissociation is observed, as demonstrated in Equation 4.
  • the salts of acrylic acid and methacrylic acid are more susceptible to protonation, shifting the reaction equilibrium of Equation 5 towards the right. The protonation of the salts of acrylic acid and methacrylic acid takes up a portion of the protons generated from the dissociation of hydrochloric acid in forming acrylic acid and methacrylic acid.
  • the N atom of the nitrile group in copolymer chain 101 is found to interact with the H atom of the carboxyl group in the same copolymer chain via hydrogen bonding interactions. Furthermore, hydrogen bond is formed between the H atom of the amide group and the O atom of the carbonyl group of the carboxyl group within copolymer chain 101. Meanwhile, hydrogen bonding is also developed between the H atom of the carboxyl group and the O atom of the amide group within copolymer chain 201.
  • Figure 4 illustrates a schematic of an embodiment of the proposed alterations in interactions between the polymer and the aqueous solvent outlined in Figure 1 with the addition of an insufficient amount or concentration of precipitation agent into the first suspension, forming a second suspension of a higher pH.
  • the polymer compound in bold represents an embodiment of the polymer comprises a copolymer comprising structural units derived from a carboxylic acid group-containing monomer, a nitrile group-containing monomer and an amide group-containing monomer.
  • the precipitation agent in this case comprises hydrochloric acid, which is a type of strong acid; while the aqueous solvent in this scenario comprises water.
  • the hydrochloric acid dissociates and generates hydroxonium ions upon addition of the acid into the first suspension in forming a second suspension.
  • the acid used is rather diluted, and thus the pH of the second suspension in this case is 5, which implies the presence of a significantly lower concentration of hydroxonium ions in the second suspension than that of in Figure 2.
  • the low concentration of hydroxonium ions in the second suspension is insufficient in breaking up the intermolecular attractions that were formerly developed between the polymer and the water molecules as shown in Figure 1.
  • part of the hydrogen bonds formed between the water molecules at the solvation shells around the copolymer chain remain, which impedes the access of the copolymer chain to other copolymer chains in developing interactions.
  • the acid group-containing monomer that assists in the make-up of the polymer as illustrated in Figure 4 comprises an acrylic acid and a methacrylic acid.
  • the small amount of hydroxonium ions in the second suspension is only capable of transforming a portion of the salts of acrylic acid and methacrylic acid into their uncharged acid forms. This allows some of the ion-dipole interactions between the acid salt group-containing monomers and the water molecules to persist in the first suspension. Furthermore, intramolecular attractions between functional groups within the same copolymer chain occur in a lesser extent which arises from the inadequate bond disruption between the polymer and the water molecules. All of these circumstances make the coil-to-globule structural conformation of the polymer particularly challenging, and thus the precipitation of the polymer could not be achieved.
  • Figure 5 illustrates a schematic of an embodiment of the proposed alterations in interactions between a polymer which comprises a copolymer comprising structural unit (s) derived from one or more carboxylic acid group-containing monomer (s) and the aqueous solvent as sufficient concentration of precipitation agent is added into the first suspension.
  • the polymer compound in bold represents the polymer.
  • the precipitation agent in this case comprises hydrochloric acid, which is a type of strong acid; while the aqueous solvent in this scenario comprises water.
  • the denotation R 1 , R 2 , R 3 and R 4 in Figure 5 independently has the general formula C n H 2n , where n is an integer that is greater than 0.
  • H atoms in the above general formula can be unsubstituted or substituted with one or more suitable substituents and does not affect the functionality of the entire polymer.
  • R 1 , R 2 , R 3 and R 4 can be independently the same or different from one another.
  • hydrochloric acid Upon the addition of hydrochloric acid into the first suspension, the acid dissociates and produces hydroxonium ions, leading to the formation of a second suspension.
  • the entire copolymer chain comprising structural unit (s) derived from only acid group-containing monomer (s) , a large amount of the protons is taken up to protonate the acid salt groups of the polymer into acid groups. Therefore, a considerable amount of hydroxonium ions is reverted into water molecules in regions near the polymer which allows the formation of hydrogen bonds between the acid group-containing monomer (s) that assists in the construction of the polymer and the water molecules.
  • the method of the present invention is specifically developed to precipitate a polymer, wherein the polymer comprises a copolymer comprising a structural unit (a) derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • a structural unit derived from an acid group-containing monomer a structural unit derived from a hydrophobic group-containing monomer.
  • An example of a hydrophobic group-containing monomer is a nitrile group-containing monomer.
  • the polymer comprising only a structural unit derived from a nitrile group-containing monomer would be inherently hydrophobic throughout the entire polymer chain, and thus would not be miscible with water to begin with.
  • This polymer type is known as non-aqueous polymer.
  • the method of the present invention is not applicable to the precipitation of a non-aqueous polymer.
  • the first suspension comprises a polymer and an aqueous solvent.
  • the polymer comprises a copolymer. The polymer is soluble in water and some other aqueous solvents.
  • the copolymer comprises at least one structural unit derived from a polar group-containing monomer.
  • Structural units derived from monomers containing at least one polar group govern the types and strength of the intermolecular interactions (e.g. dipole-dipole interactions and hydrogen bonding) developed between the polymer and the aqueous solvent and could possibly enhance the dissolution of the polymer in an aqueous solvent in forming a first suspension.
  • Structural units derived from an acid group-containing monomer, a nitrile group-containing monomer, an amide group-containing monomer, a hydroxyl group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine-containing monomer or combinations thereof comprised within the copolymer in the polymer constitute some non-limiting examples of functional groups that can form intermolecular interactions (e.g. hydrogen bonding) with the constituents of the aqueous solvent.
  • the polar group-containing monomer is selected from the group consisting of an acid group-containing monomer and a nitrile group-containing monomer. In some embodiments, the polar group-containing monomer is selected from the group consisting of an acid group-containing monomer, a nitrile group-containing monomer, an amide group-containing monomer or combinations thereof. In some embodiments, the polar group-containing monomer is selected from the group consisting of an acid group-containing monomer, a nitrile group-containing monomer, an amide group-containing monomer, a hydroxyl group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine-containing monomer or combinations thereof.
  • the polar group-containing monomer is selected from the group consisting of an amide group-containing monomer, a hydroxyl group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine-containing monomer or combinations thereof.
  • the copolymer does not comprise a structural unit derived from an amide group-containing monomer, a hydroxyl group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine-containing monomer or combinations thereof.
  • the proportion of structural unit derived from a polar group-containing monomer is from about 40%to about 100%, from about 45%to about 100%, from about 50%to about 100%, from about 55%to about 100%, from about 60%to about 100%, from about 65%to about 100%, from about 70%to about 100%, from about 40%to about 95%, from about 45%to about 95%, from about 50%to about 95%, from about 55%to about 95%, from about 60%to about 95%, from about 65%to about 95%, from about 40%to about 90%, from about 45%to about 90%, from about 50%to about 90%, from about 55%to about 90%, from about 60%to about 90%, from about 40%to about 85%, from about 45%to about 85%, from about 50%to about 85%, from about 55%to about 85%, from about 40%to about 80%, from about 45%to about 80%, from about 50%to about 80%, from about 40%to about 75%, from about 40%to about 70%or from about 45%to about 75%by mole, based on the total number
  • the proportion of structural unit derived from a polar group-containing monomer is less than 100%, less than 95%, less than 90%, less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%or less than 45%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the proportion of structural unit derived from a polar group-containing monomer is more than 40%, more than 45%, more than 50%, more than 55%, more than 60%, more than 65%, more than 70%, more than 75%, more than 80%, more than 85%, more than 90%or more than 95%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the polymer comprises a copolymer comprising at least one structural unit derived from a hydrophilic group-containing monomer and at least one structural unit derived from a hydrophobic group-containing monomer.
  • the hydrophilic group-containing monomer is selected from the group consisting of an acid group-containing monomer. In some embodiments, the hydrophilic group-containing monomer is selected from the group consisting of an acid group-containing monomer, an amide group-containing monomer, a hydroxyl group-containing monomer or combinations thereof. In some embodiments, the hydrophilic group-containing monomer is selected from the group consisting of an amide group-containing monomer, a hydroxyl group-containing monomer or combinations thereof.
  • the hydrophobic group-containing monomer is selected from the group consisting of a nitrile group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine group-containing monomer or combinations thereof.
  • Hydrophilic functional group (s) are extremely soluble in water.
  • the presence of a hydrophilic functional group in a structural unit in the polymer provides extents of hydrophilic features towards the overall properties of the entire copolymer chain of the polymer, potentially improving the solubility of the polymer in water.
  • the proportion of structural unit derived from a hydrophilic group-containing monomer in the copolymer is critical in regulating the dissolution of the polymer in the aqueous solvent.
  • This polymer type is designated as a non-aqueous polymer.
  • hydrophobic functional group (s) in the polymer exert extents of hydrophobic effect to the polymer which allows the aggregation of segment (s) of the polymer to avoid contact with water molecules or an aqueous solvent.
  • a structural unit derived from a hydrophobic group-containing monomer provokes the winding of the polymer into a globular structural conformation.
  • the polymer would not be capable of undergoing a coil-to-globule structural transformation due to the lack of a hydrophobic functional group that is required to trigger the change in polymer conformation and initiate phase transition of the polymer.
  • the polymer would be extremely insoluble in water and deemed as a non-aqueous polymer. Such polymer would not be covered by the scope of the present invention.
  • the proportion of each of structural unit derived from a hydrophilic group-containing monomer and structural unit derived from a hydrophobic group-containing monomer is independently from about 0%to about 85%, from about 0%to about 80%, from about 0%to about 75%, from about 0%to about 70%, from about 0%to about 65%, from about 0%to about 60%, from about 0%to about 55%, from about 0%to about 50%, from about 0%to about 45%, from about 0%to about 40%, from about 0%to about 35%, from about 5%to about 85%, from about 5%to about 80%, from about 5%to about 75%, from about 5%to about 70%, from about 5%to about 65%, from about 5%to about 60%, from about 5%to about 55%, from about 5%to about 50%, from about 5%to about 45%, from about 5%to about 40%, from about 5%to about 35%, from about 10%to about 85%, from about 10%to about 80%, from about 10%to about 7
  • the proportion of each of structural unit derived from a hydrophilic group-containing monomer and structural unit derived from a hydrophobic group-containing monomer is independently less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%or less than 5%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the proportion of each of structural unit derived from a hydrophilic group-containing monomer and structural unit derived from a hydrophobic group-containing monomer is independently more than 0%, more than 5%, more than 10%, more than 15%, more than 20%, more than 25%, more than 30%, more than 35%, more than 40%, more than 45%, more than 50%, more than 55%, more than 60%, more than 65%, more than 70%, more than 75%or more than 80%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the hydrophilic group-containing monomer is selected from the group consisting of an acid group-containing monomer, an amide group-containing monomer, a hydroxyl group-containing monomer or combinations thereof.
  • the ratio in the proportion of the structural unit derived from a hydrophilic group-containing monomer to the proportion of the structural unit derived from a hydrophobic group-containing monomer in the copolymer is delicate and is integral to the likelihood of the polymer in undergoing conformational change with the addition of a precipitation agent into the first suspension.
  • the molar ratio of the structural unit derived from a hydrophilic group-containing monomer to the structural unit derived from a hydrophobic group-containing monomer in the copolymer is from about 0.1 to about 6.5, from about 0.1 to about 6.4, from about 0.1 to about 6.2, from about 0.1 to about 6, from about 0.1 to about 5.8, from about 0.1 to about 5.6, from about 0.1 to about 5.4, from about 0.1 to about 5.2, from about 0.1 to about 5, from about 0.1 to about 4.8, from about 0.1 to about 4.6, from about 0.1 to about 4.4, from about 0.1 to about 4.2, from about 0.1 to about 4, from about 0.1 to about 3.8, from about 0.1 to about 3.6, from about 0.1 to about 3.4, from about 0.1 to about 3.2, from about 0.1 to about 3, from about 0.1 to about 2.8, from about 0.1 to about 2.6, from about 0.1 to about 2.4, from about 0.1 to about 2.2, from about 0.1 to about
  • the molar ratio of the structural unit derived from a hydrophilic group-containing monomer to the structural unit derived from a hydrophobic group-containing monomer in the copolymer is less than 6.5, less than 6.4, less than 6.3, less than 6.2, less than 6.1, less than 6, less than 5.9, less than 5.8, less than 5.7, less than 5.6, less than 5.5, less than 5.4, less than 5.3, less than 5.2, less than 5.1, less than 5, less than 4.9, less than 4.8, less than 4.7, less than 4.6, less than 4.5, less than 4.4, less than 4.3, less than 4.2, less than 4.1, less than 4, less than 3.9, less than 3.8, less than 3.7, less than 3.6, less than 3.5, less than 3.4, less than 3.3, less than 3.2, less than 3.1, less than 3, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3
  • the molar ratio of the structural unit derived from a hydrophilic group-containing monomer to the structural unit derived from a hydrophobic group-containing monomer in the copolymer is more than 0.1, more than 0.2, more than 0.3, more than 0.4, more than 0.5, more than 0.6, more than 0.7, more than 0.8, more than 0.9, more than 1, more than 1.1, more than 1.2, more than 1.3, more than 1.4, more than 1.5, more than 1.6, more than 1.7, more than 1.8, more than 1.9, more than 2, more than 2.1, more than 2.2, more than 2.3, more than 2.4, more than 2.5, more than 2.6, more than 2.7, more than 2.8, more than 2.9, more than 3, more than 3.1, more than 3.2, more than 3.3, more than 3.4, more than 3.5, more than 3.6, more than 3.7, more than 3.8, more than 3.9, more than 4, more than 4.1, more than 4.2, more than 4.3
  • the molar ratio of the structural unit derived from an acid group-containing monomer to the structural unit derived from a hydrophobic group-containing monomer in the copolymer is from about 0.1 to about 3, from about 0.1 to about 2.9, from about 0.1 to about 2.8, from about 0.1 to about 2.7, from about 0.1 to about 2.6, from about 0.1 to about 2.5, from about 0.1 to about 2.4, from about 0.1 to about 2.3, from about 0.1 to about 2.2, from about 0.15 to about 3, from about 0.15 to about 2.9, from about 0.15 to about 2.8, from about 0.15 to about 2.7, from about 0.15 to about 2.6, from about 0.15 to about 2.5, from about 0.15 to about 2.4, from about 0.15 to about 2.3, from about 0.15 to about 2.2, from about 0.2 to about 3, from about 0.2 to about 2.9, from about 0.2 to about 2.8, from about 0.2 to about 2.7, from about 0.2 to about 2.6, from about 0.2 to about 2.5,
  • the molar ratio of the structural unit derived from an acid group-containing monomer to the structural unit derived from a hydrophobic group-containing monomer in the copolymer is less than 3, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, less than 0.3 or less than 0.2.
  • the molar ratio of the structural unit derived from an acid group-containing monomer to the structural unit derived from a hydrophobic group-containing monomer in the copolymer is more than 0.1, more than 0.2, more than 0.3, more than 0.4, more than 0.5, more than 0.6, more than 0.7, more than 0.8, more than 0.9, more than 1, more than 1.1, more than 1.2, more than 1.3, more than 1.4, more than 1.5, more than 1.6, more than 1.7, more than 1.8 or more than 1.9.
  • the copolymer comprises a structural unit (a) derived from an acid group-containing monomer and a structural unit (b) derived from a nitrile group-containing monomer. In some embodiments, the copolymer comprises a structural unit (a) derived from an acid group-containing monomer, a structural unit (b) derived from a nitrile group-containing monomer, a structural unit (c) derived from an amide group-containing monomer or combinations thereof.
  • the copolymer further comprises a structural unit (d) derived from a hydroxyl group-containing monomer, a structural unit (e) derived from an ester group-containing monomer, a structural unit (f) derived from an epoxy group-containing monomer, a structural unit (g) derived from a fluorine-containing monomer or combinations thereof.
  • Structural unit (a) is derived from an acid group-containing monomer. Any monomer that has at least one acid group may be used as acid group-containing monomer without any specific limitations.
  • the acid group-containing monomer is a carboxylic acid group-containing monomer.
  • the carboxylic acid group-containing monomer is acrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic acid or a combination thereof.
  • the carboxylic acid group-containing monomer is 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglic acid, 3, 3-dimethyl acrylic acid, 3-propyl acrylic acid, trans-2-methyl-3-ethyl acrylic acid, cis-2-methyl-3-ethyl acrylic acid, 3-isopropyl acrylic acid, trans-3-methyl-3-ethyl acrylic acid, cis-3-methyl-3-ethyl acrylic acid, 2-isopropyl acrylic acid, trimethyl acrylic acid, 2-methyl-3, 3- diethyl acrylic acid, 3-butyl acrylic acid, 2-butyl acrylic acid, 2-pentyl acrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-methyl-3-propyl acrylic acid, 2-ethyl-3-propyl acrylic acid, 2, 3-diethyl acrylic acid, 3, 3-diethyl acrylic acid, 3-diethyl
  • the carboxylic acid group-containing monomer is methyl maleic acid, dimethyl maleic acid, phenyl maleic acid, bromo maleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoro maleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate or a combination thereof.
  • the carboxylic acid group-containing monomer is maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, acrylic anhydride, methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, or a combination thereof.
  • structural unit (a) derived from a carboxylic acid group-containing monomer comprises a carboxylic salt group.
  • a carboxylic salt group is a salt of a carboxylic acid group.
  • structural unit (a) derived from a carboxylic acid group-containing monomer comprises an alkali metal carboxylic salt group. Examples of an alkali metal forming the alkali metal carboxylic salt include lithium, sodium and potassium.
  • structural unit (a) derived from a carboxylic acid group-containing monomer comprises an ammonium carboxylic salt group.
  • structural unit (a) derived from a carboxylic acid group-containing monomer comprises a combination of a carboxylic salt group and a carboxylic acid group.
  • any monomer that has at least one carboxylic salt group may be used as carboxylic salt group-containing monomer without any specific limitations.
  • the carboxylic salt group-containing monomer is acrylic acid salt, methacrylic acid salt, crotonic acid salt, 2-butyl crotonic acid salt, cinnamic acid salt, maleic acid salt, maleic anhydride salt, fumaric acid salt, itaconic acid salt, itaconic anhydride salt, tetraconic acid salt or a combination thereof.
  • the carboxylic salt group-containing monomer is 2-ethylacrylic acid salt, isocrotonic acid salt, cis-2-pentenoic acid salt, trans-2-pentenoic acid salt, angelic acid salt, tiglic acid salt, 3, 3-dimethyl acrylic acid salt, 3-propyl acrylic acid salt, trans-2-methyl-3-ethyl acrylic acid salt, cis-2-methyl-3-ethyl acrylic acid salt, 3-isopropyl acrylic acid salt, trans-3-methyl-3-ethyl acrylic acid salt, cis-3-methyl-3-ethyl acrylic acid salt, 2-isopropyl acrylic acid salt, trimethyl acrylic acid salt, 2-methyl-3, 3-diethyl acrylic acid salt, 3- butyl acrylic acid salt, 2-butyl acrylic acid salt, 2-pentyl acrylic acid salt, 2-methyl-2-hexenoic acid salt, trans-3-methyl-2-hexenoic acid salt, 3-methyl-3-propyl acrylic acid salt, 2-ethyl-3-propyl
  • the carboxylic salt group-containing monomer is methyl maleic acid salt, dimethyl maleic acid salt, phenyl maleic acid salt, bromo maleic acid salt, chloromaleic acid salt, dichloromaleic acid salt, fluoromaleic acid salt, difluoro maleic acid salt or a combination thereof.
  • the acid group-containing monomer is a sulfonic acid group-containing monomer.
  • the sulfonic acid group-containing monomer is vinylsulfonic acid, methylvinylsulfonic acid, allylvinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, 2-sulfoethyl methacrylic acid, 2-methylprop-2-ene-1-sulfonic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, 3-allyloxy-2-hydroxy-1-propane sulfonic acid or a combination thereof.
  • structural unit (a) derived from a sulfonic acid group-containing monomer comprises a sulfonic salt group.
  • a sulfonic salt group is a salt of a sulfonic acid group.
  • structural unit (a) derived from a sulfonic acid group-containing monomer comprises an alkali metal sulfonic salt group. Examples of an alkali metal forming the alkali metal sulfonic salt include lithium, sodium and potassium.
  • structural unit (a) derived from a sulfonic acid group-containing monomer comprises an ammonium sulfonic salt group.
  • structural unit (a) derived from a sulfonic acid group-containing monomer comprises a combination of a sulfonic salt group and a sulfonic acid group.
  • any monomer that has at least one sulfonic salt group may be used as sulfonic salt group-containing monomer without any specific limitations.
  • the sulfonic salt group-containing monomer is vinylsulfonic acid salt, methylvinylsulfonic acid salt, allylvinylsulfonic acid salt, allylsulfonic acid salt, methallylsulfonic acid salt, styrenesulfonic acid salt, 2-sulfoethyl methacrylic acid salt, 2-methylprop-2-ene-1-sulfonic acid salt, 2-acrylamido-2-methyl-1-propane sulfonic acid salt, 3-allyloxy-2-hydroxy-1-propane sulfonic acid salt or a combination thereof.
  • the acid group-containing monomer is a phosphonic acid group-containing monomer.
  • the phosphonic acid group-containing monomer is vinyl phosphonic acid, allyl phosphonic acid, vinyl benzyl phosphonic acid, acrylamide alkyl phosphonic acid, methacrylamide alkyl phosphonic acid, acrylamide alkyl diphosphonic acid, acryloylphosphonic acid, 2-methacryloyloxyethyl phosphonic acid, bis (2-methacryloyloxyethyl) phosphonic acid, ethylene 2-methacryloyloxyethyl phosphonic acid, ethyl-methacryloyloxyethyl phosphonic acid or a combination thereof.
  • structural unit (a) derived from a phosphonic acid group-containing monomer comprises a phosphonic salt group.
  • a phosphonic salt group is a salt of a phosphonic acid group.
  • structural unit (a) derived from a phosphonic acid group-containing monomer comprises an alkali metal phosphonic salt group. Examples of an alkali metal forming the alkali metal phosphonic salt include lithium, sodium and potassium.
  • structural unit (a) derived from a phosphonic acid group-containing monomer comprises an ammonium phosphonic salt group.
  • structural unit (a) derived from a phosphonic acid group-containing monomer comprises a combination of a phosphonic salt group and a phosphonic acid group.
  • the phosphonic salt group-containing monomer is salt of vinyl phosphonic acid, salt of allyl phosphonic acid, salt of vinyl benzyl phosphonic acid, salt of acrylamide alkyl salt of phosphonic acid, salt of methacrylamide alkyl phosphonic acid, salt of acrylamide alkyl diphosphonic acid, salt of acryloylphosphonic acid, salt of 2-methacryloyloxyethyl phosphonic acid, salt of bis (2-methacryloyloxyethyl) phosphonic acid, salt of ethylene 2-methacryloyloxyethyl phosphonic acid, salt of ethyl-methacryloyloxyethyl phosphonic acid or a combination thereof.
  • the structural unit (a) is derived from a carboxylic acid group-containing monomer, a sulfonic acid group-containing monomer, a phosphonic acid group-containing monomer or a combination thereof.
  • structural unit (a) derived from an acid group-containing monomer comprises an acid salt group.
  • an acid salt group is a salt of an acid group. Any monomer that has at least one acid salt group may be used as acid salt group-containing monomer without any specific limitations.
  • the acid salt group-containing monomer is selected from the group consisting of a carboxylic salt group-containing monomer, a sulfonic salt group-containing monomer, a phosphonic salt group-containing monomer or a combination thereof.
  • structural unit (a) derived from an acid group-containing monomer comprises an alkali metal acid salt group. Examples of an alkali metal forming the alkali metal acid salt include lithium, sodium and potassium.
  • structural unit (a) derived from an acid group-containing monomer comprises an ammonium acid salt group.
  • structural unit (a) derived from an acid group-containing monomer comprises a combination of an acid salt group and an acid group.
  • structural unit (a) derived from an acid group-containing monomer comprises atom (s) that is/are capable of forming hydrogen bond (s) .
  • structural unit (a) derived from an acid group-containing monomer further comprises charged species that is/are capable of inducing ion-dipole interactions and/or forming ionic bond (s) .
  • an acid group undergoes partial dissociation when comes into contact with water and produces an acid salt group that contains charged species, giving rise to the formation of ion-dipole interactions and/or ionic bond (s) .
  • the proportion of structural unit (a) derived from an acid group-containing monomer is from about 15%to about 85%, from about 15%to about 84%, from about 15%to about 83%, from about 15%to about 82%, from about 15%to about 81%, from about 15%to about 80%, from about 15%to about 79%, from about 15%to about 78%, from about 15%to about 77%, from about 15%to about 76%, from about 15%to about 75%, from about 15%to about 74%, from about 15%to about 73%, from about 15%to about 72%, from about 15%to about 71%, from about 15%to about 70%, from about 15%to about 65%, from about 15%to about 60%, from about 15%to about 55%, from about 15%to about 50%, from about 16%to about 85%, from about 17%to about 85%, from about 18%to about 85%, from about 19%to about 85%, from about 20%to about 85%, from about 21%to about 85%, from about 22%to about 85%, from about 25%to about 85%, from about 30%to
  • the proportion of structural unit (a) derived from an acid group-containing monomer is less than 85%, less than 84%, less than 82%, less than 80%, less than 78%, less than 76%, less than 74%, less than 72%, less than 70%, less than 68%, less than 66%, less than 64%, less than 62%, less than 60%, less than 58%, less than 56%, less than 54%, less than 52%, less than 50%, less than 48%, less than 46%, less than 44%, less than 42%, less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%or less than 18%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the proportion of structural unit (a) derived from an acid group-containing monomer is more than 15%, more than 16%, more than 18%, more than 20%, more than 22%, more than 24%, more than 26%, more than 28%, more than 30%, more than 32%, more than 34%, more than 36%, more than 38%, more than 40%, more than 42%, more than 44%, more than 46%, more than 48%, more than 50%, more than 52%, more than 54%, more than 56%, more than 58%, more than 60%, more than 62%, more than 64%, more than 66%, more than 68%, more than 70%, more than 72%, more than 74%, more than 76%, more than 78%, more than 80%or more than 82%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the pK a specifies the strength of an acid.
  • a lower pK a value indicates a stronger acid, that is, an acid which dissociates more fully in an aqueous solvent such as water. It is desirable for the strength of the acid group-containing monomer (s) that contribute to the make-up of the polymer to be lower than that of the acid that is utilized as a precipitation agent to facilitate the deprotonation of the precipitation agent and the protonation of the conjugate base of the acid group-containing monomer (s) . For this reason, the pK a value of the acid group-containing monomer should be higher than that of the acid to be utilized as a precipitation agent.
  • the pK a of the acid group-containing monomer is from about 2.5 to about 7, from about 2.5 to about 6.8, from about 2.5 to about 6.6, from about 2.5 to about 6.4, from about 2.5 to about 6.2, from about 2.5 to about 6, from about 2.5 to about 5.8, from about 2.5 to about 5.6, from about 2.5 to about 5.4, from about 2.5 to about 5.2, from about 2.5 to about 5, from about 2.5 to about 4.8, from about 2.5 to about 4.6, from about 2.5 to about 4.4, from about 2.5 to about 4.2, from about 2.5 to about 4, from about 2.6 to about 7, from about 2.6 to about 6.8, from about 2.6 to about 6.6, from about 2.6 to about 6.4, from about 2.6 to about 6.2, from about 2.6 to about 6, from about 2.6 to about 5.8, from about 2.6 to about 5.6, from about 2.6 to about 5.4, from about 2.6 to about 5.2, from about 2.6 to about 5, from about 2.6 to about 4.8, from about 2.6 to about 4.6, from about 2.6 to about 4.4
  • the pK a of the acid group-containing monomer is less than 7, less than 6.8, less than 6.6, less than 6.4, less than 6.2, less than 6, less than 5.8, less than 5.6, less than 5.4, less than 5.2, less than 5, less than 4.8, less than 4.6, less than 4.4, less than 4.2, less than 4, less than 3.8, less than 3.6, less than 3.4, less than 3.2, less than 3, less than 2.8 or less than 2.6.
  • the pK a of the acid group-containing monomer is more than 2.5, more than 2.6, more than 2.8, more than 3, more than 3.2, more than 3.4, more than 3.6, more than 3.8, more than 4, more than 4.2, more than 4.4, more than 4.6, more than 4.8, more than 5, more than 5.2, more than 5.4, more than 5.6, more than 5.8, more than 6, more than 6.2, more than 6.4, more than 6.6 or more than 6.8.
  • Structural unit (b) is derived from a nitrile group-containing monomer. Any monomer that has at least one nitrile group may be used as nitrile group-containing monomer without any specific limitations.
  • the nitrile group-containing monomer include ⁇ , ⁇ -ethylenically unsaturated nitrile monomers.
  • the nitrile group-containing monomer is acrylonitrile, ⁇ -halogenoacrylonitrile, ⁇ -alkylacrylonitrile or a combination thereof.
  • the nitrile group-containing monomer is ⁇ -chloroacrylonitrile, ⁇ -bromoacrylonitrile, ⁇ -fluoroacrylonitrile, methacrylonitrile, ⁇ -ethylacrylonitrile, ⁇ -isopropylacrylonitrile, ⁇ -n-hexylacrylonitrile, ⁇ -methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, ⁇ -acetoxyacrylonitrile, ⁇ -phenylacrylonitrile, ⁇ -tolylacrylonitrile, ⁇ - (methoxyphenyl) acrylonitrile, ⁇ - (chlorophenyl) acrylonitrile, ⁇ - (cyanophenyl) acrylonitrile, vinylidene cyanide, or a combination thereof.
  • the proportion of structural unit (b) derived from a nitrile group-containing monomer is from about 15%to about 85%, from about 15%to about 84%, from about 15%to about 83%, from about 15%to about 82%, from about 15%to about 81%, from about 15%to about 80%, from about 15%to about 79%, from about 15%to about 78%, from about 15%to about 77%, from about 15%to about 76%, from about 15%to about 75%, from about 15%to about 74%, from about 15%to about 73%, from about 15%to about 72%, from about 15%to about 71%, from about 15%to about 70%, from about 15%to about 65%, from about 15%to about 60%, from about 15%to about 55%, from about 15%to about 50%, from about 16%to about 85%, from about 17%to about 85%, from about 18%to about 85%, from about 19%to about 85%, from about 20%to about 85%, from about 21%to about 85%, from about 22%to about 85%, from about 25%to about 85%,
  • the proportion of structural unit (b) derived from a nitrile group-containing monomer is less than 85%, less than 84%, less than 82%, less than 80%, less than 78%, less than 76%, less than 74%, less than 72%, less than 70%, less than 68%, less than 66%, less than 64%, less than 62%, less than 60%, less than 58%, less than 56%, less than 54%, less than 52%, less than 50%, less than 48%, less than 46%, less than 44%, less than 42%, less than 40%, less than 38%, less than 36%, less than 34%, less than 32%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%or less than 16%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the proportion of structural unit (b) derived from a nitrile group-containing monomer is more than 15%, more than 16%, more than 18%, more than 20%, more than 22%, more than 24%, more than 26%, more than 28%, more than 30%, more than 32%, more than 34%, more than 36%, more than 38%, more than 40%, more than 42%, more than 44%, more than 46%, more than 48%, more than 50%, more than 52%, more than 54%, more than 56%, more than 58%, more than 60%, more than 62%, more than 64%, more than 66%, more than 68%, more than 70%, more than 72%, more than 74%, more than 76%, more than 78%, more than 80%or more than 82%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • Structural unit (c) is derived from an amide group-containing monomer. Any monomer that has at least one amide group may be used as amide group-containing monomer without any specific limitations.
  • the amide group-containing monomer is acrylamide, methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, N-n-propyl methacrylamide, N-isopropyl methacrylamide, isopropyl acrylamide, N-n-butyl methacrylamide, N-isobutyl methacrylamide, N, N-dimethyl acrylamide, N, N-dimethyl methacrylamide, N, N-diethyl acrylamide, N, N-diethyl methacrylamide, N-methylol methacrylamide, N- (methoxymethyl) methacrylamide, N- (ethoxymethyl) methacrylamide, N- (propoxymethyl) methacrylamide, N- (butoxymethyl) methacrylamide,
  • the proportion of structural unit (c) derived from an amide group-containing monomer is from about 0%to about 35%, from about 1%to about 35%, from about 2%to about 35%, from about 3%to about 35%, from about 4%to about 35%, from about 5%to about 35%, from about 6%to about 35%, from about 7%to about 35%, from about 8%to about 35%, from about 9%to about 35%, from about 10%to about 35%, from about 11%to about 35%, from about 12%to about 35%, from about 13%to about 35%, from about 14%to about 35%, from about 15%to about 35%, from about 16%to about 35%, from about 17%to about 35%, from about 18%to about 35%, from about 19%to about 35%, from about 20%to about 35%, from about 20%to about 34%, from about 20%to about 33%, from about 20%to about 32%, from about 20%to about 31%, from about 20%to about 30%, from about 0%to about 35%,
  • the proportion of structural unit (c) derived from an amide group-containing monomer is less than 35%, less than 34%, less than 33%, less than 32%, less than 31%, less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, less than 11%or less than 10%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • the proportion of structural unit (c) derived from an amide group-containing monomer is more than 0%, more than 1%, more than 2%, more than 3%, more than 4%, more than 5%, more than 6%, more than 7%, more than 8%, more than 9%, more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24%or more than 25%by mole, based on the total number of moles of monomeric units in the copolymer in the polymer.
  • Structural unit (d) is derived from a hydroxyl group-containing monomer. Any monomer that has at least one hydroxyl group may be used as hydroxyl group-containing monomer without any specific limitations.
  • the hydroxyl group-containing monomer is a C 1 to C 20 alkyl group or a C 5 to C 20 cycloalkyl group-containing methacrylate having a hydroxyl group.
  • the hydroxyl group-containing monomer is 2-hydroxyethylacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropylacrylate, 3-hydroxypropylmethacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentylacrylate, 6-hydroxyhexyl methacrylate, 1, 4-cyclohexanedimethanol mono (meth) acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol mono (meth) acrylate, allyl alcohol or a combination thereof.
  • Structural unit (e) is derived from an ester group-containing monomer. Any monomer that has at least one ester group may be used as ester group-containing monomer without any specific limitations.
  • the ester group-containing monomer is C 1 to C 20 alkyl acrylate, C 1 to C 20 alkyl (meth) acrylate, cycloalkyl acrylate or a combination thereof.
  • the ester group-containing monomer is methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 3, 3, 5-trimethylhexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, oxtadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate, perfluoroocty
  • the ester group-containing monomer is cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, 3, 3, 5-trimethylcyclohexylacrylate, or a combination thereof.
  • the ester group-containing monomer is methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, stearyl methacrylate, 2, 2, 2-trifluoroethyl methacrylate, phenyl methacrylate, benzyl methacrylate, or a combination thereof.
  • Structural unit (f) is derived from an epoxy group-containing monomer. Any monomer that has at least one epoxy group may be used as epoxy group-containing monomer without any specific limitations.
  • the epoxy group-containing monomer is vinyl glycidyl ether, allyl glycidyl ether, allyl 2, 3-epoxypropyl ether, butenyl glycidyl ether, butadiene monoepoxide, chloroprene monoepoxide, 3, 4-epoxy-1-butene, 4, 5-epoxy-2-pentene, 3, 4-epoxy-1-vinylcyclohexane, 1, 2-epoxy-4-vinylcyclohexane, 3, 4-epoxy cyclohexylethylene, epoxy-4-vinylcyclohexene, 1, 2-epoxy-5, 9-cyclododecadiene or a combination thereof.
  • the epoxy group-containing monomer is 3, 4-epoxy-1-butene, 1, 2-epoxy-5-hexene, 1, 2-epoxy-9-decene, glycidyl acrylate, glycidyl methacrylate, glycidyl crotonate, glycidyl 2, 4-dimethyl pentenoate, glycidyl 4-hexenoate, glycidyl 4-heptenoate, glycidyl 5-methyl-4-heptenoate, glycidyl sorbate, glycidyl linoleate, glycidyl oleate, glycidyl 3-butenoate, glycidyl 3-pentenoate, glycidyl-4-methyl-3-pentenoate or a combination thereof.
  • Structural unit (g) is derived from a fluorine-containing monomer. Any monomer that has at least one fluorine atom may be used as fluorine-containing monomer without any specific limitations.
  • the fluorine-containing monomer is a C 1 to C 20 alkyl group-containing acrylate, methacrylate or a combination thereof having at least one fluorine atom.
  • the fluorine-containing monomer is perfluoro alkyl acrylate such as perfluoro dodecyl acrylate, perfluoro n-octyl acrylate, perfluoro n-butyl acrylate, perfluoro hexylethyl acrylate and perfluoro octylethyl acrylate; perfluoro alkyl methacrylate such as perfluoro dodecyl methacrylate, perfluoro n-octyl methacrylate, perfluoro n-butyl methacrylate, perfluoro hexylethyl methacrylate and perfluoro octylethyl methacrylate; perfluoro oxyalkyl acrylate such as perfluoro dodecyloxyethyl acrylate and perfluoro decyloxyethyl acrylate; perfluoro oxyalkyl me
  • the fluorine-containing monomer is a carboxylate containing at least one C 1 to C 20 alkyl group and at least one fluorine atom; wherein the carboxylate is selected from the group consisting of crotonate, malate, fumarate, itaconate or a combination thereof.
  • the fluorine-containing monomer is vinyl fluoride, trifluoroethylene, trifluorochloroethylene, fluoroalkyl vinyl ether, perfluoroalkyl vinyl ether, hexafluoropropylene, 2, 3, 3, 3-tetrafluoropropene, vinylidene fluoride, tetrafluoroethylene, 2-fluoro acrylate and combinations thereof.
  • the proportion of each of structural unit (d) derived from a hydroxyl group-containing monomer, structural unit (e) derived from an ester group-containing monomer, structural unit (f) derived from an epoxy group-containing monomer and structural unit (g) derived from a fluorine-containing monomer is independently from about 0%to about 50%, from about 1%to about 50%, from about 2%to about 50%, from about 3%to about 50%, from about 4%to about 50%, from about 5%to about 50%, from about 6%to about 50%, from about 7%to about 50%, from about 8%to about 50%, from about 9%to about 50%, from about 10%to about 50%, from about 11%to about 50%, from about 12%to about 50%, from about 13%to about 50%, from about 14%to about 50%, from about 15%to about 50%, from about 16%to about 50%, from about 17%to about 50%, from about 18%to about 50%, from about 19%to about 50%, from about 20%to about 50%, from about 20%to about 49%, from
  • the proportion of each of structural unit (d) derived from a hydroxyl group-containing monomer, structural unit (e) derived from an ester group-containing monomer, structural unit (f) derived from an epoxy group-containing monomer and structural unit (g) derived from a fluorine-containing monomer is independently less than 50%, less than 49%, less than 48%, less than 47%, less than 46%, less than 45%, less than 44%, less than 43%, less than 42%, less than 41%, less than 40%, less than 39%, less than 38%, less than 37%, less than 36%, less than 35%, less than 34%, less than 33%, less than 32%, less than 31%, less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%,
  • the proportion of each of structural unit (d) derived from a hydroxyl group-containing monomer, structural unit (e) derived from an ester group-containing monomer, structural unit (f) derived from an epoxy group-containing monomer and structural unit (g) derived from a fluorine-containing monomer is independently more than 0%, more than 1%, more than 2%, more than 3%, more than 4%, more than 5%, more than 6%, more than 7%, more than 8%, more than 9%, more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24%, more than 25%, more than 26%, more than 27%, more than 28%, more than 29%, more than 30%, more than 31%, more than 32%, more than 33%, more than 34%, more than 35%
  • the copolymer may additionally comprise a structural unit derived from an olefin. Any hydrocarbon that has at least one carbon-carbon double bond may be used as an olefin without any specific limitations.
  • the olefin includes a C 2 to C 20 aliphatic compound, a C 8 to C 20 aromatic compound or a cyclic compound containing vinylic unsaturation, a C 4 to C 40 diene or a combination thereof.
  • the olefin is styrene, ethylene, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, cyclobutene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4, 6-dimethyl-1-heptene, 4-vinylcyclohexene, vinyl cyclohexane, norbornene, norbornadiene, ethylidene norbornene, cyclopentene, cyclohexene, dicyclopentadiene, cyclooctene or a combination thereof.
  • the copolymer does not comprise a structural unit derived from an olefin. In some embodiments, the copolymer does not comprise styrene, ethylene, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, cyclobutene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4, 6-dimethyl-1-heptene, 4-vinylcyclohexene, vinyl cyclohexane, norbornene, norbornadiene, ethylidene norbornene, cyclopentene, cyclohexene, dicyclopentadiene or cyclooc
  • a conjugated diene group-containing monomer constitutes as an olefin.
  • a conjugated diene group-containing monomer is C 4 to C 40 dienes, aliphatic conjugated diene monomers such as 1, 3-butadiene, 1, 3-pentadiene, 1, 4-hexadiene, 1, 5-hexadiene, 1, 7-octadiene, 1, 9-decadiene, isoprene, myrcene, 2-methyl-1, 3-butadiene, 2, 3-dimethyl-1, 3-butadiene, 2-chloro-1, 3-butadiene, substituted linear conjugated pentadienes, substituted side chain conjugated hexadienes or a combination thereof.
  • the copolymer does not comprise C 4 to C 40 dienes, aliphatic conjugated diene monomers such as 1, 3-butadiene, 1, 3-pentadiene, 1, 4-hexadiene, 1, 5-hexadiene, 1, 7-octadiene, 1, 9-decadiene, isoprene, myrcene, 2-methyl-1, 3-butadiene, 2, 3-dimethyl-1, 3-butadiene, 2-chloro-1, 3-butadiene, substituted linear conjugated pentadienes or substituted side chain conjugated hexadienes.
  • aliphatic conjugated diene monomers such as 1, 3-butadiene, 1, 3-pentadiene, 1, 4-hexadiene, 1, 5-hexadiene, 1, 7-octadiene, 1, 9-decadiene, isoprene, myrcene, 2-methyl-1, 3-butadiene, 2, 3-dimethyl-1, 3-butadiene, 2-chloro-1,
  • the copolymer may additionally comprise a structural unit derived from an aromatic vinyl group-containing monomer.
  • the aromatic vinyl group-containing monomer is styrene, ⁇ -methylstyrene, vinyltoluene, divinylbenzene or a combination thereof.
  • the copolymer does not comprise a structural unit derived from an aromatic vinyl group-containing monomer.
  • the copolymer does not comprise styrene, ⁇ -methylstyrene, vinyltoluene or divinylbenzene.
  • the weight average molecular weight of the polymer is from about 50,000 g/mol to about 200,000 g/mol, from about 55,000 g/mol to about 200,000 g/mol, from about 60,000 g/mol to about 200,000 g/mol, from about 65,000 g/mol to about 200,000 g/mol, from about 70,000 g/mol to about 200,000 g/mol, from about 75,000 g/mol to about 200,000 g/mol, from about 80,000 g/mol to about 200,000 g/mol, from about 85,000 g/mol to about 200,000 g/mol, from about 90,000 g/mol to about 200,000 g/mol, from about 90,000 g/mol to about 190,000 g/mol, from about 90,000 g/mol to about 180,000 g/mol, from about 90,000 g/mol to about 170,000 g/mol, from about 90,000 g/mol to about 160,000 g/mol, from about 95,000 g/mol to about
  • the weight average molecular weight of the polymer is less than 200,000 g/mol, less than 195,000 g/mol, less than 190,000 g/mol, less than 185,000 g/mol, less than 180,000 g/mol, less than 175,000 g/mol, less than 170,000 g/mol, less than 165,000 g/mol, less than 160,000 g/mol, less than 155,000 g/mol, less than 150,000 g/mol, less than 145,000 g/mol, less than 140,000 g/mol, less than 135,000 g/mol, less than 130,000 g/mol, less than 125,000 g/mol, less than 120,000 g/mol, less than 115,000 g/mol, less than 110,000 g/mol, less than 105,000 g/mol, less than 100,000 g/mol, less than 95,000 g/mol, less than 90,000 g/mol, less than 85,000 g/mol, less than 80,000 g/mol, less than 75,000 g/mol, less than
  • the weight average molecular weight of the polymer is more than 50,000 g/mol, more than 55,000 g/mol, more than 60,000 g/mol, more than 65,000 g/mol, more than 70,000 g/mol, more than 75,000 g/mol, more than 80,000 g/mol, more than 85,000 g/mol, more than 90,000 g/mol, more than 95,000 g/mol, more than 100,000 g/mol, more than 105,000 g/mol, more than 110,000 g/mol, more than 115,000 g/mol, more than 120,000 g/mol, more than 125,000 g/mol, more than 130,000 g/mol, more than 135,000 g/mol, more than 140,000 g/mol, more than 145,000 g/mol, more than 150,000 g/mol, more than 155,000 g/mol, more than 160,000 g/mol, more than 165,000 g/mol, more than 170,000 g/mol, more than 175,000 g/mol, more than 180,000
  • the number average molecular weight of the polymer is from about 10,000 g/mol to about 100,000 g/mol, from about 15,000 g/mol to about 100,000 g/mol, from about 20,000 g/mol to about 100,000 g/mol, from about 25,000 g/mol to about 100,000 g/mol, from about 30,000 g/mol to about 100,000 g/mol, from about 35,000 g/mol to about 100,000 g/mol, from about 40,000 g/mol to about 100,000 g/mol, from about 45,000 g/mol to about 100,000 g/mol, from about 50,000 g/mol to about 100,000 g/mol, from about 50,000 g/mol to about 95,000 g/mol, from about 50,000 g/mol to about 90,000 g/mol, from about 50,000 g/mol to about 85,000 g/mol, from about 50,000 g/mol to about 80,000 g/mol, from about 55,000 g/mol to about 80,000 g/mol, from about 60,000 g/mol to
  • the number average molecular weight of the polymer is less than 100,000 g/mol, less than 95,000 g/mol, less than 90,000 g/mol, less than 85,000 g/mol, less than 80,000 g/mol, less than 75,000 g/mol, less than 70,000 g/mol, less than 65,000 g/mol, less than 60,000 g/mol, less than 55,000 g/mol, less than 50,000 g/mol, less than 45,000 g/mol, less than 40,000 g/mol, less than 35,000 g/mol, less than 30,000 g/mol, less than 25,000 g/mol, less than 20,000 g/mol or less than 15,000 g/mol.
  • the number average molecular weight of the polymer is more than 10,000 g/mol, more than 15,000 g/mol, more than 20,000 g/mol, more than 25,000 g/mol, more than 30,000 g/mol, more than 35,000 g/mol, more than 40,000 g/mol, more than 45,000 g/mol, more than 50,000 g/mol, more than 55,000 g/mol, more than 60,000 g/mol, more than 65,000 g/mol, more than 70,000 g/mol, more than 75,000 g/mol, more than 80,000 g/mol, more than 85,000 g/mol, more than 90,000 g/mol or more than 95,000 g/mol.
  • the polydispersity index (PDI) of the polymer is from about 1 to about 5, from about 1 to about 4.8, from about 1 to about 4.6, from about 1 to about 4.4, from about 1 to about 4.2, from about 1 to about 4, from about 1 to about 3.8, from about 1 to about 3.6, from about 1 to about 3.4, from about 1 to about 3.2, from about 1 to about 3, from about 1.1 to about 3, from about 1.2 to about 3, from about 1.3 to about 3, from about 1.4 to about 3, from about 1.5 to about 3, from about 1.6 to about 3, from about 1.6 to about 2.8, from about 1.6 to about 2.6, from about 1.8 to about 2.6 or from about 1.8 to about 2.8.
  • the polydispersity index of the polymer is less than 5, less than 4.8, less than 4.6, less than 4.4, less than 4.2, less than 4, less than 3.8, less than 3.6, less than 3.4, less than 3.2, less than 3, less than 2.8, less than 2.6, less than 2.4, less than 2.2, less than 2, less than 1.8, less than 1.6, less than 1.4 or less than 1.2.
  • the polydispersity index of the polymer is more than 1, more than 1.2, more than 1.4, more than 1.6, more than 1.8, more than 2, more than 2.2, more than 2.4, more than 2.6, more than 2.8, more than 3, more than 3.2, more than 3.4, more than 3.6, more than 3.8, more than 4, more than 4.2, more than 4.4, more than 4.6 or more than 4.8.
  • the aqueous solvent is a solution containing water as the major component and a volatile solvent, such as alcohols, lower aliphatic ketones, lower alkyl acetates or the like, as the minor component in addition to water.
  • the proportion of water in the aqueous solvent is from about 51%to about 100%, from about 51%to about 95%, from about 51%to about 90%, from about 51%to about 85%, from about 51%to about 80%, from about 51%to about 75%, from about 51%to about 70%, from about 55%to about 100%, from about 55%to about 95%, from about 55%to about 90%, from about 55%to about 85%, from about 55%to about 80%, from about 60%to about 100%, from about 60%to about 95%, from about 60%to about 90%, from about 60%to about 85%, from about 60%to about 80%, from about 65%to about 100%, from about 65%to about 95%, from about 65%to about 90%, from about 65%to about 85%, from from about 65%to about
  • the proportion of water in the aqueous solvent is more than 50%, more than 55%, more than 60%, more than 65%, more than 70%, more than 75%, more than 80%, more than 85%, more than 90%or more than 95%by weight. In some embodiments, the proportion of water in the aqueous solvent is less than 55%, less than 60%, less than 65%, less than 70%, less than 75%, less than 80%, less than 85%, less than 90%or less than 95%by weight. In some embodiments, the aqueous solvent consists solely of water, that is, the proportion of water in the aqueous solvent is 100%by weight.
  • water examples include tap water, bottled water, purified water, pure water, distilled water, de-ionized water, D 2 O, or a combination thereof.
  • the aqueous solvent is de-ionized water. Water forms solvation shells around various charged, partially charged or polar species present in the polymer and consequently promotes the dissolution of the polymer in the first suspension.
  • any water-miscible solvents or volatile solvents can be used as the minor component (i.e. solvents other than water) of the aqueous solvent.
  • the water-miscible solvents or volatile solvents include alcohols, lower aliphatic ketones, lower alkyl acetates and combinations thereof.
  • the addition of alcohol can improve the solubility of the polymer and lower the freezing point of water.
  • Some non-limiting examples of the alcohol include C 1 -C 4 alcohols, such as methanol, ethanol, isopropanol, n-propanol, tert-butanol, n-butanol and combinations thereof.
  • the lower aliphatic ketones include acetone, dimethyl ketone, methyl ethyl ketone (MEK) and combinations thereof.
  • Some non-limiting examples of the lower alkyl acetates include ethyl acetate (EA) , isopropyl acetate, propyl acetate, butyl acetate (BA) and combinations thereof.
  • the aqueous solvent does not comprise an alcohol, a lower aliphatic ketone, a lower alkyl acetate or combinations thereof.
  • the method of the present invention is directed towards achieving precipitation of a polymer by (1) disrupting and/or breaking the intermolecular attractions (e.g. hydrogen bonding and/or ion-dipole interactions) between the polymer and the aqueous solvent via the use of a precipitation agent and (2) consequently inducing a coil-to-globule structural transformation of the polymer.
  • disrupting and/or breaking the intermolecular attractions e.g. hydrogen bonding and/or ion-dipole interactions
  • a precipitation agent is added into the first suspension to form a second suspension.
  • the precipitation agent is an acid. In some embodiments, the precipitation agent is a strong acid, a weak acid or a combination thereof.
  • the precipitation agent is a strong acid. Strong acid is one that fully or almost fully dissociates in water in producing hydrogen ions as described in Equation 1.
  • the strong acid is an inorganic acid.
  • the inorganic acid is selected from the group consisting of nitric acid, sulphuric acid, hydrochloric acid, perchloric acid, hydrobromic acid, hydroiodic acid, chloric acid, bromic acid, iodic acid, dithionic acid, dithionous acid, sulfamic acid, trithionic acid, tetrathionic acid or combinations thereof.
  • the strong acid is selected from the group consisting of methane sulphonic acid, p-toluenesulfonic acid, benzene sulfonic acid, trichloroacetic acid, trifluoroacetic acid, oxalic acid, propiolic acid, mesoxalic acid, mellitic acid or combinations thereof.
  • the strength of the acid that is utilized as a precipitation agent is highly recommended for the strength of the acid that is utilized as a precipitation agent to be higher than that of the acid group-containing monomer (s) that assists the construction of the polymer to promote the preferential dissociation of the precipitation agent and the protonation of the conjugate base of the acid group-containing monomer (s) . Accordingly, the pK a value of the acid as a precipitation agent should be lower than that of the acid group-containing monomer.
  • the pK a of the strong acid is from about -10 to about 2, from about -9.5 to about 2, from about -9 to about 2, from about -8.5 to about 2, from about -8 to about 2, from about -7.5 to about 2, from about -7 to about 2, from about -6.5 to about 2, from about -6 to about 2, from about -5.5 to about 2, from about -5 to about 2, from about -4.8 to about 2, from about -4.6 to about 2, from about -4.4 to about 2, from about -4.2 to about 2, from about -4 to about 2, from about -3.8 to about 2, from about -3.6 to about 2, from about -3.4 to about 2, from about -3.2 to about 2, from about -3 to about 2, from about -3 to about 2, from about -2.8 to about 2, from about -2.6 to about 2, from about -2.4 to about 2, from about -2.2 to about 2, from about -2 to about 2, from about -1.8 to about 2, from about -1.6 to about 2, from about -1.4 to about 2, from about -1.2 to about 2, from
  • the pK a of the strong acid is less than 2, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4, less than 0.3, less than 0.2, less than 0.1, less than 0, less than -0.5, less than -1, less than -1.5, less than -2, less than -2.5, less than -3, less than -3.5, less than -4, less than -4.5, less than -5, less than -5.5, less than -6, less than -6.5, less than -7, less than -8, less than -8.5, less than -9 or less than -9.5.
  • the pK a of the strong acid is more than -10, more than -9.5, more than -9, more than -8.5, more than -8, more than -7.5, more than -7, more than -6.5, more than -6, more than -5.5, more than -5, more than -4.5, more than -4, more than -3.5, more than -3, more than -2.5, more than -2, more than -1.5, more than -1, more than -0.5, more than 0, more than 0.1, more than 0.2, more than 0.3, more than 0.4, more than 0.5, more than 0.6, more than 0.7, more than 0.8, more than 0.9, more than 1, more than 1.1, more than 1.2, more than 1.3, more than 1.4, more than 1.5, more than 1.6, more than 1.7, more than 1.8 or more than 1.9.
  • the pK a of the strong acid is between -10 and 2, between 9.5 and 2, between -9 and 2, between -8.5 and 2, between -8 and 2, between -7.5 and 2, between -7 and 2, between -6.5 and 2, between -6 and 2, between -5.5 and 2, between -5 and 2, between -4.5 and 2, between -4 and 2, between -3.5 and 2, between -3 and 2, between -2.5 and 2 or between -2 and 2.
  • a polyprotic acid is utilized as a precipitation agent.
  • a polyprotic acid refers to an acid that has two or more ionizable hydrogen ions (i.e. protons) per molecule.
  • Some non-limiting examples of polyprotic acid include sulphuric acid, dithionic acid, dithionous acid, trithionic acid, tetrathionic acid, oxalic acid, malonic acid, tartronic acid, dihydroxymalonic acid, mesoxalic acid, butanedioic acid, methylmalonic acid, fumaric acid, maleic acid, 2-hydroxybutanedioic acid, tartaric acid, oxaloacetic acid, dioxosuccinic acid, glutaric acid, 2-oxoglutaric acid, 3-oxoglutaric acid, hexanedioic acid, citric acid, aconitic acid, isocitric acid, pimelic acid, trimesic acid, mellitic acid, mal
  • polyprotic strong acid examples include sulphuric acid, oxalic acid, mellitic acid, mesoxalic acid, dithionic acid, dithionous acid, trithionic acid and tetrathionic acid.
  • sulphuric acid In a sulphuric acid, there are two protons that could be dissociated per molecule. With sulphuric acid having a pK a of -2.80 in attaining first proton dissociation, sulphuric acid is regarded as a strong acid. With the second proton in sulphuric acid dissociates at a pK a of 1.99, sulphuric acid after the dissociation of the first proton is still a strong acid, and thus it is necessary to consider the dissociation of the second protons. Therefore, the proton concentration premised on the dissociation from sulphuric acid is calculated based on the dissociation of both protons from one molecule of sulphuric acid.
  • the strong acid specifically refers to an acid with a pK a of -10 to 2 or between -10 and 2.
  • a polyprotic strong acid is an acid with a pK a of from about -10 to about 2 for the dissociation of the first proton, second proton, third proton or combinations thereof.
  • a polyprotic strong acid is an acid with a pK a of between -10 and 2 for the dissociation of the first proton, second proton, third proton or combinations thereof.
  • the pH value of the second suspension specifies the concentration of hydroxonium ions contained within.
  • the pH value of the second suspension governs the states (i.e. protonated or deprotonated form) in which different acids predominantly exist when placed in the second suspension. For example, in the case where the pH of the second suspension is lower than the pK a of an acid A but higher than the pK a of an acid B, acid A would mainly exist in the second suspension in its protonated form, while acid B would primarily exist in its deprotonated form.
  • the pK a of the acid it would be highly favorable for the pK a of the acid to be utilized as the precipitation agent and the pH of the second suspension to be lower than the pKa value (s) of the acid group-containing monomer (s) that contribute the make-up of the polymer.
  • This enables the dissociation of the precipitation agent and the preferential protonation of the conjugate base of the acid group-containing monomer (existing in the second suspension in its protonated form) , and thus consequently assists the separation of the polymer from the aqueous solvent and the structural transformation of the polymer.
  • the pH of the second suspension is from about 0.2 to about 4.5, from about 0.2 to about 4.4, from about 0.2 to about 4.3, from about 0.2 to about 4.1, from about 0.2 to about 4, from about 0.2 to about 3.8, from about 0.2 to about 3.6, from about 0.2 to about 3.4, from about 0.2 to about 3.2, from about 0.2 to about 3, from about 0.2 to about 2.8, from about 0.2 to about 2.6, from about 0.2 to about 2.4, from about 0.2 to about 2.2, from about 0.2 to about 2, from about 0.2 to about 1.8, from about 0.2 to about 1.6, from about 0.2 to about 1.4, from about 0.2 to about 1.2, from about 0.4 to about 4.5, from about 0.4 to about 4.5, from about 0.4 to about 4.3, from about 0.4 to about 4.1, from about 0.4 to about 4, from about 0.4 to about 0.4 to about
  • the pH of the second suspension is less than 4.5, less than 4.4, less than 4.3, less than 4.2, less than 4.1, less than 4, less than 3.9, less than 3.8, less than 3.7, less than 3.6, less than 3.5, less than 3.4, less than 3.3, less than 3.2, less than 3.1, less than 3, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4 or less than 0.3.
  • the pH of the second suspension is more than 0.2, more than 0.3, more than 0.4, more than 0.5, more than 0.6, more than 0.7, more than 0.8, more than 0.9, more than 1, more than 1.1, more than 1.2, more than 1.3, more than 1.4, more than 1.5, more than 1.6, more than 1.7, more than 1.8, more than 1.9, more than 2, more than 2.1, more than 2.2, more than 2.3, more than 2.4, more than 2.5, more than 2.6, more than 2.7, more than 2.8, more than 2.9, more than 3, more than 3.1, more than 3.2, more than 3.3, more than 3.4, more than 3.5, more than 3.6, more than 3.7, more than 3.8, more than 3.9, more than 4, more than 4.1, more than 4.2, more than 4.3 or more than 4.4.
  • Figures 6A and 6B depict the physical conditions of second suspensions of Comparative Example 1 and Example 2 with a pH of 6 and 3 respectively after the addition of a precipitation agent into a first suspension in forming the second suspensions.
  • sulphuric acid is being utilized as the precipitation agent which has a pK a value of -2.8.
  • the polymer comprises a copolymer comprising structural units derived from a carboxylic acid group-containing monomer, a nitrile group-containing monomer and an amide group-containing monomer.
  • the structural unit derived from a carboxylic acid group-containing monomer comprises an acrylic acid salt.
  • Acrylic acid has a pKa value of 4.3.
  • the presence of charge-bearing acrylic acid salt that contribute the make-up of the polymer allows for the persistence of the ion-dipole interactions between the polymer and the aqueous solvent and at the same time imparts an electrostatic repulsion throughout the copolymer chain, hindering the coil-to-globule structural transformation of the polymer.
  • the polymer thus could not be precipitated out from the second suspension.
  • the sulphuric acid would exist in the second suspension in its deprotonated form.
  • the presence of uncharged acrylic acid that assists in the construction of the polymer helps eliminate or significantly reduces the ion-dipole interactions between the polymer and the aqueous solvent and simultaneously initiates the aggregation of the polymer. As a result, precipitation of the polymer occurs.
  • Figures 7A and 7B illustrate the infrared spectroscopy of the precipitated polymer and the remaining of the second suspension of Example 38 respectively.
  • the polymer comprises structural units derived from a carboxylic acid group-containing monomer, a nitrile group-containing monomer and an amide group-containing monomer.
  • Figure 7A is used for the identification of the precipitated chemical substances by detecting the various functional groups present within.
  • Figure 7B is used to uncover the effectiveness and quality of precipitation of the polymer from the second suspension, i.e. to find out if the polymer is still present in the remaining of the second suspension. None of the characteristic peaks associated with a nitrile group, an amide group and a carboxylic group that correspond to the polymer is found in the infra-red spectrum in Figure 7B. It is evident that no observable polymer is present in the remainder of the second suspension. This provides evidence that the method of the present invention is highly effective in precipitating the polymer, avoids contamination of the polymer and enables excellent materials recovery.
  • the precipitation agent is a weak acid.
  • Weak acid is one that does not fully ionize or dissociate to produce hydrogen ions when dissolved in water.
  • the weak acid is an organic acid.
  • the organic acid is selected from the group consisting of formic acid, acetic acid, glycolic acid, glyoxylic acid, oxalic acid, propionic acid, acrylic acid, lactic acid, 3-hydroxipropionic acid, glyceric acid, pyruvic acid, 3-oxopropionic acid, 2, 3-dioxopropionic acid, malonic acid, tartronic acid, dihydroxymalonic acid, mesoxalic acid, glycidic acid, butyric acid, isobutyric acid, crotonic acid, isocrotonic acid, methacrylic acid, vinylacetic acid, tetrolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-oxobutanoic acid
  • the weak acid is phosphoric acid, nitrous acid, orthosilicic acid or combinations thereof.
  • the pK a of the weak acid is from about 2 to about 7, from about 2.2 to about 7, from about 2.4 to about 7, from about 2.6 to about 7, from about 2.8 to about 7, from about 3 to about 7, from about 3.2 to about 7, from about 3.4 to about 7, from about 3.6 to about 7, from about 3.8 to about 7, from about 4 to about 7, from about 2 to about 6.5, from about 2.2 to about 6.5, from about 2.4 to about 6.5, from about 2.6 to about 6.5, from about 2.8 to about 6.5, from about 3 to about 6.5, from about 3.2 to about 6.5, from about 3.4 to about 6.5, from about 3.6 to about 6.5, from about 3.8 to about 6.5, from about 4 to about 6.5, from about 2 to about 6, from about 2.2 to about 6, from about 2.4 to about 6, from about 2.6 to about 6, from about 2.8 to about 6, from about 3 to about 6, from about 3.2 to about 6, from about 3.4 to about 6, from about 3.6 to about 6, from about 3.8 to about 6, from about 4 to about
  • the pK a of the weak acid is less than 7, less than 6.5, less than 6, less than 5.5, less than 5.4, less than 5.3, less than 5.2, less than 5.1, less than 5, less than 4.9, less than 4.8, less than 4.7, less than 4.6, less than 4.5, less than 4.4, less than 4.3, less than 4.2, less than 4.1, less than 4, less than 3.9, less than 3.8, less than 3.7, less than 3.6, less than 3.5, less than 3.4, less than 3.3, less than 3.2, less than 3.1, less than 3, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2 or less than 2.1.
  • the pK a of the weak acid is more than 2, more than 2.1, more than 2.2, more than 2.3, more than 2.4, more than 2.5, more than 2.6, more than 2.7, more than 2.8, more than 2.9, more than 3, more than 3.1, more than 3.2, more than 3.3, more than 3.4, more than 3.5, more than 3.6, more than 3.7, more than 3.8, more than 3.9, more than 4, more than 4.1, more than 4.2, more than 4.3, more than 4.4, more than 4.5, more than 4.6, more than 4.7, more than 4.8, more than 4.9, more than 5, more than 5.1, more than 5.2, more than 5.3, more than 5.4, more than 5.5, more than 6 or more than 6.5.
  • the pK a of the weak acid is between 2 and 7, between 2 and 6.5, between 2 and 6, between 2 and 5.5, between 2 and 5.4, between 2 and 5.2, between 2 and 5, between 2 and 4.8, between 2 and 4.6, between 2 and 4.4, between 2 and 4.2 or between 2 and 4.
  • polyprotic weak acid examples include oxalic acid, malonic acid, tartronic acid, dihydroxymalonic acid, mesoxalic acid, butanedioic acid, methylmalonic acid, fumaric acid, maleic acid, 2-hydroxybutanedioic acid, tartaric acid, oxaloacetic acid, dioxosuccinic acid, glutaric acid, 2-oxoglutaric acid, 3-oxoglutaric acid, hexanedioic acid, citric acid, aconitic acid, isocitric acid, pimelic acid, trimesic acid, mellitic acid, malic acid, dithionous acid and orthosilicic acid.
  • a phosphoric acid there are three protons that could be dissociated per molecule.
  • phosphoric acid having a pK a of 2.12 in attaining first proton dissociation phosphoric acid is regarded as a weak acid.
  • the second proton in phosphoric acid dissociates at a pK a of 7.21 and the third at a pK a of 12.32, phosphoric acid after the dissociation of the first proton is no longer a weak acid, and thus it is not necessary to consider the dissociation of the second and subsequent protons. Therefore, the proton concentration premised on the dissociation from phosphoric acid is calculated assuming that only one proton dissociates from one molecule of phosphoric acid.
  • the weak acid specifically refers to an acid with a pK a of 2 to 7 or between 2 and 7.
  • a polyprotic weak acid is an acid with a pK a of from about 2 to about 7 for the dissociation of the first proton, second proton, third proton or combinations thereof.
  • a polyprotic weak acid is an acid with a pK a of between 2 and 7 for the dissociation of the first proton, second proton, third proton or combinations thereof.
  • oxalic acid there are two protons that could be dissociated per molecule.
  • oxalic acid having a pK a of 1.25 in attaining first proton dissociation, oxalic acid is regarded as a strong acid.
  • the second proton in oxalic acid dissociates at a pK a of 3.81, oxalic acid after the dissociation of the first proton is a weak acid. Therefore, the proton concentration premised on the dissociation from oxalic acid is calculated based on the dissociation of the first proton and partial dissociation of the second proton from one molecule of oxalic acid.
  • An oxalic acid therefore, could be regarded as both a polyprotic strong acid (associated with the dissociation of the first proton) and a polyprotic weak acid (related to the dissociation of the second proton) .
  • the pH of the second suspension is from about 0.5 to about 3, from about 0.5 to about 2.9, from about 0.5 to about 2.8, from about 0.5 to about 2.7, from about 0.5 to about 2.6, from about 0.5 to about 2.5, from about 0.5 to about 2.4, from about 0.5 to about 2.3, from about 0.5 to about 2.2, from about 0.5 to about 2.1, from about 0.5 to about 2, from about 0.5 to about 1.9, from about 0.5 to about 1.8, from about 0.5 to about 1.7, from about 0.5 to about 1.6, from about 0.5 to about 1.5, from about 0.6 to about 3, from about 0.6 to about 2.9, from about 0.6 to about 2.8, from about 0.6 to about 2.7, from about 0.6 to about 2.6, from about 0.6 to about 2.5, from about 0.6 to about 2.4, from about 0.6 to about 2.3, from about 0.6 to about 2.2
  • the pH of the second suspension is less than 3, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1, less than 0.9, less than 0.8, less than 0.7 or less than 0.6.
  • the pH of the second suspension is more than 0.5, more than 0.6, more than 0.7, more than 0.8, more than 0.9, more than 1, more than 1.1, more than 1.2, more than 1.3, more than 1.4, more than 1.5, more than 1.6, more than 1.7, more than 1.8, more than 1.9, more than 2, more than 2.1, more than 2.2, more than 2.3, more than 2.4, more than 2.5, more than 2.6, more than 2.7, more than 2.8 or more than 2.9.
  • the pH of the second suspension is from about 0.2 to about 4.5, from about 0.2 to about 4.4, from about 0.2 to about 4.3, from about 0.2 to about 4.1, from about 0.2 to about 4, from about 0.2 to about 3.8, from about 0.2 to about 3.6, from about 0.2 to about 3.4, from about 0.2 to about 3.2, from about 0.2 to about 3, from about 0.2 to about 2.8, from about 0.2 to about 2.6, from about 0.2 to about 2.4, from about 0.2 to about 2.2, from about 0.2 to about 2, from about 0.2 to about 1.8, from about 0.2 to about 1.6, from about 0.2 to about 1.4, from about 0.2 to about 1.2, from about 0.4 to about 4.5, from about 0.4 to about 4.5, from about 0.4 to about 4.3, from about 0.4 to about 4.1, from about 0.4 to about 4, from about 0.4 to about 3.8, from about 0.4 to about 3.6, from about 0.4 to about 3.4, from about 0.4 to about 3.2
  • the pH of the second suspension is less than 4.5, less than 4.4, less than 4.3, less than 4.2, less than 4.1, less than 4, less than 3.9, less than 3.8, less than 3.7, less than 3.6, less than 3.5, less than 3.4, less than 3.3, less than 3.2, less than 3.1, less than 3, less than 2.9, less than 2.8, less than 2.7, less than 2.6, less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2, less than 1.9, less than 1.8, less than 1.7, less than 1.6, less than 1.5, less than 1.4, less than 1.3, less than 1.2, less than 1.1, less than 1, less than 0.9, less than 0.8, less than 0.7, less than 0.6, less than 0.5, less than 0.4 or less than 0.3.
  • the pH of the second suspension is more than 0.2, more than 0.3, more than 0.4, more than 0.5, more than 0.6, more than 0.7, more than 0.8, more than 0.9, more than 1, more than 1.1, more than 1.2, more than 1.3, more than 1.4, more than 1.5, more than 1.6, more than 1.7, more than 1.8, more than 1.9, more than 2, more than 2.1, more than 2.2, more than 2.3, more than 2.4, more than 2.5, more than 2.6, more than 2.7, more than 2.8, more than 2.9, more than 3, more than 3.1, more than 3.2, more than 3.3, more than 3.4, more than 3.5, more than 3.6, more than 3.7, more than 3.8, more than 3.9, more than 4, more than 4.1, more than 4.2, more than 4.3 or more than 4.4.
  • the pH of the second suspension is from about 0.2 pH unit to about 6.8 pH units, from about 0.2 pH unit to about 6.5 pH units, from about 0.2 pH unit to about 6 pH units, from about 0.2 pH unit to about 5.5 pH units, from about 0.2 pH unit to about 5 pH units, from about 0.2 pH unit to about 4.5 pH units, from about 0.2 pH unit to about 4 pH units, from about 0.2 pH unit to about 3.5 pH units, from about 0.2 pH unit to about 3 pH units, from about 0.2 pH unit to about 2.5 pH units, from about 0.2 pH unit to about 2 pH units, from about 0.5 pH unit to about 6.8 pH units, from about 0.5 pH unit to about 6.5 pH units, from about 0.5 pH unit to about 6 pH units, from about 0.5 pH unit to about 5.5 pH units, from about 0.5 pH unit to about 5 pH units, from about 0.5 pH unit to about 4.5 pH units, from about 0.5 pH unit to about 4 pH units, from about 0.5 pH unit to about 3.5 pH units, from about 0.5 pH unit to about
  • the pH of the second suspension is at least 0.2 pH unit, at least 0.5 pH unit, at least 1 pH unit, at least 1.5 pH units, at least 2 pH units, at least 2.5 pH units, at least 3 pH units, at least 3.5 pH units, at least 4 pH units, at least 4.5 pH units, at least 5 pH units, at least 5.5 pH units, at least 6 pH units or at least 6.5 pH units, below the pK a of the acid group-containing monomer.
  • the pH of the second suspension is at most 6.8 pH units, at most 6.5 pH units, at most 6 pH units, at most 5.5 pH units, at most 5 pH units, at most 4.5 pH units, at most 4 pH units, at most 3.5 pH units, at most 3 pH units, at most 2.5 pH units, at most 2 pH units, at most 1.5 pH units, at most 1 pH unit or at most 0.5 pH unit, below the pK a of the acid group-containing monomer.
  • the concentration of the precipitation agent is from about 1 M to about 8 M, from about 1 M to about 7.5 M, from about 1 M to about 7 M, from about 1 M to about 6.5 M, from about 1 M to about 6 M, from about 1 M to about 5.5 M, from about 1 M to about 5 M, from about 1 M to about 4.5 M, from about 1 M to about 4 M, from about 1.5 M to about 8 M, from about 1.5 M to about 7.5 M, from about 1.5 M to about 7 M, from about 1.5 M to about 6.5 M, from about 1.5 M to about 6 M, from about 1.5 M to about 5.5 M, from about 1.5 M to about 5 M, from about 1.5 M to about 4.5 M, from about 2 M to about 8 M, from about 2 M to about 7.5 M, from about 2 M to about 7 M, from about 2 M to about 7 M, from about 2 M to about 6.5 M, from about 2 M to about 6 M, from about 2 M to about 5.5 M, from about 2 M to about 5 M, from about 2.5 M to about
  • the concentration of the precipitation agent is less than 8 M, less than 7.5 M, less than 7 M, less than 6.5 M, less than 6 M, less than 5.5 M, less than 5 M, less than 4.5 M, less than 4 M, less than 3.5 M, less than 3 M, less than 2.5 M, less than 2 M or less than 1.5 M. In some embodiments, the concentration of the precipitation agent is more than 1 M, more than 1.5 M, more than 2 M, more than 2.5 M, more than 3 M, more than 3.5 M, more than 4 M, more than 4.5 M, more than 5 M, more than 5.5 M, more than 6 M, more than 6.5 M, more than 7 M or more than 7.5 M.
  • the time allowed for the precipitation agent to induce precipitation of the polymer is crucial in attaining precipitation of the polymer in the second suspension.
  • the precipitation agent might not possess sufficient time to destabilize, disrupt and break the bonds that are initially formed between the polymer and the aqueous solvent to an extent that precipitation of the polymer is made possible.
  • the precipitation agent is being placed in the second suspension without stirring for a time period of from about 1 minute to about 180 minutes, from about 1 minute to about 160 minutes, from about 1 minute to about 140 minutes, from about 1 minute to about 120 minutes, from about 1 minute to about 110 minutes, from about 1 minute to about 100 minutes, from about 1 minute to about 90 minutes, from about 1 minute to about 80 minutes, from about 1 minute to about 70 minutes, from about 1 minute to about 60 minutes, from about 3 minutes to about 120 minutes, from about 3 minutes to about 110 minutes, from about 3 minutes to about 100 minutes, from about 3 minutes to about 90 minutes, from about 3 minutes to about 80 minutes, from about 3 minutes to about 70 minutes, from about 3 minutes to about 60 minutes, from about 5 minutes to about 120 minutes, from about 5 minutes to about 110 minutes, from about 5 minutes to about 100 minutes, from about 5 minutes to about 90 minutes, from about 5 minutes to about 80 minutes, from about 5 minutes to about 70 minutes, from about 5 minutes to about 180 minutes, from about 5 minutes to about 120 minutes, from about 5 minutes to about 110 minutes, from
  • the precipitation agent is being placed in the second suspension without stirring for a time period of less than 180 minutes, less than 160 minutes, less than 140 minutes, less than 120 minutes, less than 110 minutes, less than 100 minutes, less than 90 minutes, less than 80 minutes, less than 70 minutes, less than 60 minutes, less than 50 minutes, less than 40 minutes, less than 30 minutes, less than 20 minutes, less than 15 minutes, less than 10 minutes or less than 5 minutes.
  • the precipitation agent is being placed in the second suspension without stirring for a time period of more than 1 minute, more than 3 minutes, more than 5 minutes, more than 10 minutes, more than 15 minutes, more than 20 minutes, more than 30 minutes, more than 40 minutes, more than 50 minutes, more than 60 minutes, more than 70 minutes, more than 80 minutes, more than 90 minutes, more than 100 minutes, more than 110 minutes, more than 120 minutes, more than 140 minutes or more than 160 minutes.
  • One of the most important factors in governing the precipitation of a polymer is the temperature of the second suspension. Hydrogen bonding is primarily formed at relatively low temperatures and weakens upon an increase in temperature. In addition, hydrophobic interactions are strengthened at high temperatures. Hence, a second suspension with a slight temperature elevation can help facilitate the precipitation of a polymer via the weakening of hydrogen bonding interactions between the polymer and the aqueous solvent and the strengthening of hydrophobic interactions of the hydrophobic group-containing monomer that contribute the make-up of the polymer.
  • the precipitation agent is added into the first suspension at a temperature of from about 20 °C to about 95 °C, from about 20 °C to about 90 °C, from about 20 °C to about 85 °C, from about 20 °C to about 80 °C, from about 20 °C to about 75 °C, from about 20 °C to about 70 °C, from about 20 °C to about 65 °C, from about 20 °C to about 60 °C, from about 20 °C to about 55 °C, from about 20 °C to about 50 °C, from about 25 °C to about 95 °C, from about 25 °C to about 90 °C, from about 25 °C to about 85 °C, from about 25 °C to about 80 °C, from about 25 °C to about 75 °C, from about 25 °C to about 70 °C, from about 25 °C to about 65 °C, from about 25 °C to about 60 °C, from
  • the precipitation agent is added into the first suspension at a temperature of less than 95 °C, less than 90 °C, less than 85 °C, less than 80 °C, less than 75 °C, less than 70 °C, less than 65 °C, less than 60 °C, less than 55 °C, less than 50 °C, less than 45 °C, less than 40 °C, less than 35 °C, less than 30 °C or less than 25 °C.
  • the precipitation agent is added into the first suspension at a temperature of more than 20 °C, more than 25 °C, more than 30 °C, more than 35 °C, more than 40 °C, more than 45 °C, more than 50 °C, more than 55 °C, more than 60 °C, more than 65 °C, more than 70 °C, more than 75 °C, more than 80 °C, more than 85 °C or more than 90 °C.
  • the second suspension is being stirred to achieve precipitation of the polymer.
  • a planetary stirring mixer, a stirring mixer, a blender, an ultrasonicator or a combination thereof is being used to stir the second suspension.
  • the first suspension before the addition of the precipitation agent into the first suspension in forming a second suspension, the first suspension is being stirred to maximize the dissolution of the polymer in the aqueous solvent and allow for a more well-dispersed polymer within the first suspension.
  • a planetary stirring mixer, a stirring mixer, a blender, an ultrasonicator or a combination thereof is being used to stir the first suspension.
  • the second suspension is stirred at a speed of from about 150 rpm to about 600 rpm, from about 150 rpm to about 550 rpm, from about 150 rpm to about 500 rpm, from about 150 rpm to about 450 rpm, from about 150 rpm to about 400 rpm, from about 150 rpm to about 350 rpm, from about 200 rpm to about 600 rpm, from about 200 rpm to about 550 rpm, from about 200 rpm to about 500 rpm, from about 200 rpm to about 450 rpm, from about 200 rpm to about 400 rpm, from about 250 rpm to about 600 rpm, from about 250 rpm to about 550 rpm, from about 250 rpm to about 500 rpm, from about 250 rpm to about 450 rpm, from about 300 rpm to about 600 rpm, from about 300 rpm to about 550 rpm, from about 300 rpm to about 500 rpm, from about
  • the second suspension is stirred at a speed of less than 600 rpm, less than 580 rpm, less than 560 rpm, less than 540 rpm, less than 520 rpm, less than 500 rpm, less than 480 rpm, less than 460 rpm, less than 440 rpm, less than 420 rpm, less than 400 rpm, less than 380 rpm, less than 360 rpm, less than 340 rpm, less than 320 rpm, less than 300 rpm, less than 280 rpm, less than 260 rpm, less than 240 rpm, less than 220 rpm, less than 200 rpm or less than 180 rpm.
  • the second suspension is stirred at a speed of more than 150 rpm, more than 170 rpm, more than 200 rpm, more than 220 rpm, more than 240 rpm, more than 260 rpm, more than 280 rpm, more than 300 rpm, more than 320 rpm, more than 340 rpm, more than 360 rpm, more than 380 rpm, more than 400 rpm, more than 420 rpm, more than 440 rpm, more than 460 rpm, more than 480 rpm, more than 500 rpm, more than 520 rpm, more than 540 rpm, more than 560 rpm or more than 580 rpm.
  • the second suspension is stirred for a time period of from about 1 minute to about 180 minutes, from about 1 minute to about 150 minutes, from about 1 minute to about 120 minutes, from about 1 minute to about 100 minutes, from about 1 minute to about 80 minutes, from about 1 minute to about 60 minutes, from about 3 minutes to about 180 minutes, from about 3 minutes to about 150 minutes, from about 3 minutes to about 120 minutes, from about 3 minutes to about 100 minutes, from about 3 minutes to about 80 minutes, from about 3 minutes to about 60 minutes, from about 5 minutes to about 180 minutes, from about 5 minutes to about 150 minutes, from about 5 minutes to about 120 minutes, from about 5 minutes to about 100 minutes, from about 5 minutes to about 80 minutes, from about 5 minutes to about 60 minutes, from about 10 minutes to about 180 minutes, from about 10 minutes to about 150 minutes, from about 10 minutes to about 120 minutes, from about 10 minutes to about 100 minutes, from about 10 minutes to about 80 minutes, from about 10 minutes to about 60 minutes, from about 15 minutes to about 180 minutes, from about 15 minutes to about 150 minutes, from about 15 minutes
  • the second suspension is stirred for a time period of less than 180 minutes, less than 160 minutes, less than 140 minutes, less than 120 minutes, less than 110 minutes, less than 100 minutes, less than 90 minutes, less than 80 minutes, less than 70 minutes, less than 60 minutes, less than 50 minutes, less than 40 minutes, less than 30 minutes, less than 20 minutes, less than 15 minutes, less than 10 minutes or less than 5 minutes.
  • the second suspension is stirred for a time period of more than 1 minute, more than 3 minutes, more than 5 minutes, more than 10 minutes, more than 15 minutes, more than 20 minutes, more than 30 minutes, more than 40 minutes, more than 50 minutes, more than 60 minutes, more than 70 minutes, more than 80 minutes, more than 90 minutes, more than 100 minutes, more than 110 minutes, more than 120 minutes, more than 140 minutes or more than 160 minutes.
  • the planetary stirring mixer comprises at least one planetary blade and at least one high-speed dispersion blade.
  • the rotational speed of the planetary blade is from about 20 rpm to about 200 rpm, from about 20 rpm to about 150 rpm, from about 30 rpm to about 150 rpm, or from about 50 rpm to about 100 rpm.
  • the rotational speed of the dispersion blade is from about 1,000 rpm to about 4,000 rpm, from about 1,000 rpm to about 3,500 rpm, from about 1,000 rpm to about 3,000 rpm, from about 1,000 rpm to about 2,000 rpm, from about 1,500 rpm to about 3,000 rpm, or from about 1,500 rpm to about 2,500 rpm.
  • the ultrasonicator is an ultrasonic bath, a probe-type ultrasonicator or an ultrasonic flow cell. In some embodiments, the ultrasonicator is operated at a power density from about 10 W/L to about 100 W/L, from about 20 W/L to about 100 W/L, from about 30 W/L to about 100 W/L, from about 40 W/L to about 80 W/L, from about 40 W/L to about 70 W/L, from about 40 W/L to about 60 W/L, from about 40 W/L to about 50 W/L, from about 50 W/L to about 60 W/L, from about 20 W/L to about 80 W/L, from about 20 W/L to about 60 W/L, or from about 20 W/L to about 40 W/L.
  • the ultrasonicator is operated at a power density of more than 10 W/L, more than 20 W/L, more than 30 W/L, more than 40 W/L, more than 50 W/L, more than 60 W/L, more than 70 W/L, more than 80 W/L or more than 90 W/L.
  • the ultrasonicator operates at a power from about 100 W to about 1000 W, from about 200 W to about 1000 W, from about 300 W to about 1000 W, from about 400 W to about 1000 W, from about 500 W to about 1000 W, from about 500 W to about 900 W, from about 500 W to about 800 W, from about 500 W to about 700 W, or from about 500 W to about 600 W. In some embodiments, the ultrasonicator operates at a power of less than 1000 W, less than 900 W, less than 800 W, less than 700 W, less than 600 W, less than 500 W, less than 400 W, or less than 300 W. In some embodiments, the ultrasonicator operates at a power of more than 100 W, more than 200 W, more than 300 W, more than 400 W, more than 500 W, more than 600 W, more than 700 W, or more than 800 W.
  • the polymer is precipitated. In some embodiments, after the addition of a precipitation agent into the first suspension in forming a second suspension, the polymer is precipitated. In some embodiments, after the addition of a precipitation agent into the first suspension in forming a second suspension and with the precipitation agent being placed in the second suspension for a time period without stirring, the polymer is precipitated. In some embodiments, after the addition of a precipitation agent into the first suspension in forming a second suspension and stirring the second suspension for a time period, the polymer is precipitated.
  • the second suspension is screened to separate the precipitated polymer from the remaining of the second suspension (comprising aqueous solvent and the dissolved precipitation agent) .
  • filtration, sieving, decantation or a combination thereof may be used for screening of the second suspension.
  • Figure 9 is a flow chart of an embodiment illustrating the steps of method 900 for precipitating a polymer as disclosed herein and its subsequent further processing for extraction of the polymer.
  • the remaining of the second suspension comprising the aqueous solvent and the dissolved precipitation agent could be subjected to drying or concentration for removal of the aqueous solvent.
  • the recovered precipitation agent could be further reused for precipitation of other polymers. This allows the formation of a closed-loop recovery process where materials are repeatedly recycled and reused, and continually engage in a loop arrangement, which helps create a circular economy.
  • the method disclosed herein is specifically developed for the optimization of the polymer formulation, i.e., the composition of the polymer of the present invention is governed by the ability of the polymer to be precipitated with the addition of a precipitation agent.
  • the utilization of the method of the present invention in precipitating a polymer, wherein the polymer comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer results in a high polymer recovery rate (>98%) .
  • the polymer recovery rate refers to the proportion of the weight of the recovered polymer, based on the initial weight of polymer present in the first suspension before the addition of a precipitation agent. It serves as a reflection of the proportion of polymer retrieved and a gauge to the effectiveness of the method disclosed herein in precipitating the polymer. With the method disclosed herein yielding a high polymer recovery rate indicates that the majority of the polymer could be precipitated and retrieved with negligible amounts of polymer remaining in the second suspension.
  • the method of the present invention is particularly applicable as part of a battery electrode recycling system to achieve precipitation of a polymeric binder.
  • the battery may be a primary battery or a secondary battery.
  • the battery include alkaline battery, aluminium-air battery, lithium battery, lithium air battery, magnesium battery, solid-state battery, silver-oxide battery, zinc-air battery, aluminium-ion battery, lead-acid battery, lithium-ion battery, magnesium-ion battery, potassium-ion battery, sodium-ion battery, lithium-air battery, aluminium-air battery, zinc-air battery, sodium-air battery, silicon-air battery, zinc-ion battery and sodium-sulphur battery.
  • LIBs lithium-ion batteries
  • EV electric vehicles
  • grid energy storage high-performance, low-cost LIBs are currently offering one of the most promising options for large-scale energy storage devices.
  • Pyrometallurgical process is one of the recycling strategies that is proposed or employed for recycling end-of-life batteries, especially in the recovery of cathode constituents since cathode materials constitute the major high value added in production.
  • Pyrometallurgical process involves heating of the electrodes at high temperatures, beyond the decomposition temperature of the polymeric binder but ideally below the melting temperatures of other electrode constituents e.g. current collector and electrode active material. This process brings about the carbonization of the polymeric binder where recycling and/or reclaim of the polymeric binder is not feasible. On top of that, the combustion process might generate toxic compounds and/or pollutants produced by the decomposition of the polymeric binder. For example, in the case where an electrode that comprises polyvinylidene fluoride (PVDF) binder material undergoes pyrometallurgy, toxic compounds that could impose long-term health risks such as hydrogen fluoride would be produced. Pyrometallurgical process is also highly energy intensive and thus results in immense associated energy costs.
  • PVDF polyvinylidene fluoride
  • the method of the present invention is particularly applicable as part of a battery electrode recycling system to achieve precipitation of a polymeric binder, wherein the polymeric binder refers to the polymer disclosed herein.
  • the precipitation of the polymeric binder is attained by adding a precipitation agent into the first suspension to form a second suspension; wherein the first suspension comprises an electrode layer and an aqueous solvent; wherein the electrode layer comprises a polymeric binder; and wherein the polymeric binder comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • the method disclosed herein may be used following the delamination of an electrode, wherein the electrode comprises a current collector and an electrode layer coated on one side or both sides of the current collector comprising a polymeric binder.
  • the electrode may be a cathode or an anode.
  • the electrode layer further comprises a metal-containing material, an electrode active material or a combination thereof.
  • the recovered electrode layer is immersed and stirred in an aqueous solvent in forming a first suspension.
  • the stirring of the first suspension allows the recovered electrode layer to be broken down into small chucks or pieces to facilitate the precipitation of the polymeric binder by increasing the surface area for the precipitation agent to act upon at a later stage.
  • the first suspension comprises a polymeric binder. In some embodiments, the first suspension further comprises a metal-containing material, an electrode active material or a combination thereof.
  • the recovered electrode layer is immersed and stirred in an aqueous solvent for a time period of from about 0.25 minute to about 20 minutes, from about 0.25 minute to about 15 minutes, from about 0.25 minute to about 10 minutes, from about 0.5 minute to about 20 minutes, from about 0.5 minute to about 15 minutes, from about 0.5 minute to about 10 minutes, from about 0.75 minute to about 20 minutes, from about 0.75 minute to about 15 minutes, from about 0.75 minute to about 10 minutes, from about 1 minute to about 20 minutes, from about 1 minute to about 15 minutes, from about 1 minute to about 10 minutes, from about 2 minutes to about 20 minutes, from about 2 minutes to about 15 minutes, from about 2 minutes to about 10 minutes, from about 4 minutes to about 20 minutes, from about 4 minutes to about 15 minutes, from about 4 minutes to about 10 minutes, from about 5 minutes to about 20 minutes, from about 5 minutes to about 15 minutes, from about 5 minutes to about 10 minutes, from about 7 minutes to about 18 minutes or from about 7 minutes to about 12 minutes in
  • the recovered electrode layer is immersed and stirred in an aqueous solvent for a time period of less than 20 minutes, less than 19 minutes, less than 18 minutes, less than 17 minutes, less than 16 minutes, less than 15 minutes, less than 14 minutes, less than 13 minutes, less than 12 minutes, less than 11 minutes, less than 10 minutes, less than 9 minutes, less than 8 minutes, less than 7 minutes, less than 6 minutes, less than 5 minutes, less than 4 minutes or less than 3 minutes in forming a first suspension.
  • the recovered electrode layer is immersed and stirred in an aqueous solvent for a time period of more than 0.25 minute, more than 0.5 minute, more than 0.75 minute, more than 1 minute, more than 2 minutes, more than 3 minutes, more than 4 minutes, more than 5 minutes, more than 6 minutes, more than 7 minutes, more than 8 minutes, more than 9 minutes, more than 10 minutes, more than 11 minutes, more than 12 minutes, more than 13 minutes, more than 14 minutes, more than 15 minutes, more than 16 minutes, more than 17 minutes or more than 18 minutes in forming a first suspension.
  • an electrode layer comprises a combination of a polymeric binder and an electrode active material
  • the electrode layer that is being broken down into small chucks (also can be called as conglomerate in the present invention) by stirring in an aqueous solvent may appear as partially dissolved complex in the first suspension with parts of undissolved polymeric binder within the clusters of electrode active material or metal-containing material.
  • the method of the present invention is particularly applicable to precipitate the polymeric binder in an electrode layer manufactured via a water-based slurry.
  • the aqueous slurry utilizes a polymeric binder for adhering the active material particles and the conductive agent together with the current collector to form a continuous electrical conduction path.
  • the polymeric binder disclosed herein exhibiting an enhanced adhesive capability, which strengthen the conductive network between various components within the electrode layer, it is capable of facilitating electron and ion transportation to reduce the impedance between the current collector and the electrode materials and have sufficient elasticity to prevent the electrode from swelling due to volume expansion and contraction during charging and discharging.
  • the precipitation method disclosed herein allows the constituents of an electrode layer, e.g. a polymeric binder and an electrode active material, to be effectively separated by the simple use of a precipitation agent.
  • the polymeric binder comprises a copolymer comprising a structural unit derived from an acid group-containing monomer and a structural unit derived from a hydrophobic group-containing monomer.
  • the proportion of structural unit derived from an acid group-containing monomer and structural unit derived from a hydrophobic group-containing monomer present in the polymeric binder is independently at least 15%by mole, based on the total number of moles of monomeric units in the copolymer in the polymeric binder, which allows for the polymeric binder disclosed herein exhibiting excellent dispersibility and stability in water, and thus enhancing the binding capability of the polymeric binder.
  • the battery electrode active material is a cathode active material, wherein the cathode active material is selected from the group consisting of LiCoO 2 , LiNiO 2 , LiNi x Mn y O 2 , LiCo x Ni y O 2 , Li 1+z Ni x Mn y Co 1-x-y O 2 , LiNi x Co y Al z O 2 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , LiMnO 2 , LiCrO 2 , LiMn 2 O 4 , Li 2 MnO 3 , LiFeO 2 , LiFePO 4 , and combinations thereof, wherein each x is independently from 0.1 to 0.9; each y is independently from 0 to 0.9; each z is independently from 0 to 0.4.
  • the cathode active material is selected from the group consisting of LiCoO 2 , LiNiO 2 , LiNi x Mn y O 2 ,
  • each x in the above general formula is independently selected from 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875 and 0.9; each y in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875
  • the cathode active material is selected from the group consisting of LiCoO 2 , LiNiO 2 , LiNi x Mn y O 2 , Li 1+z Ni x Mn y Co 1-x-y O 2 (NMC) , LiNi x Co y Al z O 2 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , LiMnO 2 , LiCrO 2 , LiMn 2 O 4 , LiFeO 2 , LiFePO 4 , LiCo x Ni y O 2 , and combinations thereof, wherein each x is independently from 0.4 to 0.6; each y is independently from 0.2 to 0.4; and each z is independently from 0 to 0.1.
  • the cathode active material is not LiCoO 2 , LiNiO 2 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , LiMnO 2 , LiCrO 2 , LiMn 2 O 4 , LiFeO 2 , or LiFePO 4 .
  • the cathode active material is not LiNi x Mn y O 2 , Li 1+z Ni x Mn y Co 1-x-y O 2 , LiNi x Co y Al z O 2 or LiCo x Ni y O 2 , wherein each x is independently from 0.1 to 0.9; each y is independently from 0 to 0.45; and each z is independently from 0 to 0.2.
  • the cathode active material is Li 1+x Ni a Mn b Co c Al (1-a-b-c) O 2 ; wherein -0.2 ⁇ x ⁇ 0.2, 0 ⁇ a ⁇ 1, 0 ⁇ b ⁇ 1, 0 ⁇ c ⁇ 1, and a+b+c ⁇ 1.
  • the cathode active material has the general formula Li 1+x Ni a Mn b Co c Al (1-a-b-c) O 2 , with 0.33 ⁇ a ⁇ 0.92, 0.33 ⁇ a ⁇ 0.9, 0.33 ⁇ a ⁇ 0.8, 0.4 ⁇ a ⁇ 0.92, 0.4 ⁇ a ⁇ 0.9, 0.4 ⁇ a ⁇ 0.8, 0.5 ⁇ a ⁇ 0.92, 0.5 ⁇ a ⁇ 0.9, 0.5 ⁇ a ⁇ 0.8, 0.6 ⁇ a ⁇ 0.92, or 0.6 ⁇ a ⁇ 0.9; 0 ⁇ b ⁇ 0.5, 0 ⁇ b ⁇ 0.4, 0 ⁇ b ⁇ 0.3, 0 ⁇ b ⁇ 0.2, 0.1 ⁇ b ⁇ 0.5, 0.1 ⁇ b ⁇ 0.4, 0.1 ⁇ b ⁇ 0.3, 0.1 ⁇ b ⁇ 0.2, 0.2 ⁇ b ⁇ 0.5, 0.2 ⁇ b ⁇ 0.4, or 0.2 ⁇ b ⁇ 0.3; 0 ⁇ c ⁇ 0.5, 0 ⁇ c ⁇ 0.4, 0 ⁇ c ⁇ 0.3, 0.1 ⁇ c ⁇ 0.5, 0.1 ⁇ c ⁇ 0.4, 0.1 ⁇ c ⁇ 0.3, 0.1 ⁇ c ⁇ 0.2, 0.2 ⁇ c ⁇ 0.5, 0.2 ⁇
  • the cathode active material has the general formula LiMPO 4 , wherein M is selected from the group consisting of Fe, Co, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge and combinations thereof.
  • the cathode active material is selected from the group consisting of LiFePO 4 , LiCoPO 4 , LiNiPO 4 , LiMnPO 4 , LiMnFePO 4 , LiMn x Fe (1-x) PO 4 and combinations thereof; wherein 0 ⁇ x ⁇ 1.
  • the cathode active material is LiNi x Mn y O 4 ; wherein 0.1 ⁇ x ⁇ 0.9 and 0 ⁇ y ⁇ 2.
  • the cathode active material is xLi 2 MnO 3 ⁇ (1-x) LiMO 2 , wherein M is selected from the group consisting of Ni, Co, Mn and combinations thereof; and wherein 0 ⁇ x ⁇ 1.
  • the cathode active material is Li 3 V 2 (PO 4 ) 3 , LiVPO 4 F.
  • the cathode active material has the general formula Li 2 MSiO 4 , wherein M is selected from the group consisting of Fe, Co, Mn, Ni, and combinations thereof.
  • the cathode active material is doped with a dopant selected from the group consisting of Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof.
  • the dopant is not Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Mg, Zn, Ti, La, Ce, Ru, Si, or Ge.
  • the dopant is not Al, Sn, or Zr.
  • the cathode active material is LiNi 0.33 Mn 0.33 Co 0.33 O 2 (NMC333) , LiNi 0.4 Mn 0.4 Co 0.2 O 2 , LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532) , LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC622) , LiNi 0.7 Mn 0.15 Co 0.15 O 2 , LiNi 0.7 Mn 0.1 Co 0.2 O 2 , LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) , LiNi 0.92 Mn 0.04 Co 0.04 O 2 , LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) , LiNiO 2 (LNO) , and combinations thereof.
  • NMC333 LiNi 0.33 Mn 0.33 Co 0.33 O 2
  • NMC532 LiNi 0.4 Mn 0.4 Co 0.2 O 2
  • LiNi 0.5 Mn 0.3 Co 0.2 O 2 NMC532
  • the cathode active material is not LiCoO 2 , LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , or Li 2 MnO 3 .
  • the cathode active material is not LiNi 0.33 Mn 0.33 Co 0.33 O 2 , LiNi 0.4 Mn 0.4 Co 0.2 O 2 , LiNi 0.5 Mn 0.3 Co 0.2 O 2 , LiNi 0.6 Mn 0.2 Co 0.2 O 2 , LiNi 0.7 Mn 0.15 Co 0.15 O 2 , LiNi 0.7 Mn 0.1 Co 0.2 O 2 , LiNi 0.8 Mn 0.1 Co 0.1 O 2 , LiNi 0.92 Mn 0.04 Co 0.04 O 2 , or LiNi 0.8 Co 0.15 Al 0.05 O 2 .
  • the cathode active material comprises or is a core-shell composite having a core and shell structure, wherein the core and the shell each independently comprise a lithium transition metal oxide selected from the group consisting of Li 1+x Ni a Mn b Co c Al (1-a-b-c) O 2 , LiCoO 2 , LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 3 , LiCrO 2 , Li 4 Ti 5 O 12 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , LiCo a Ni b O 2 , LiMn a Ni b O 2 , and combinations thereof; wherein -0.2 ⁇ x ⁇ 0.2, 0 ⁇ a ⁇ 1, 0 ⁇ b ⁇ 1, 0 ⁇ c ⁇ 1, and a+b+c ⁇ 1.
  • each x in the above general formula is independently selected from -0.2, -0.175, -0.15, -0.125, -0.1, -0.075, -0.05, -0.025, 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175 and 0.2; each a in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95 and 0.975; each b in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125
  • each x, a, b and c in the above general formula independently has a 0.01 interval.
  • the core and the shell each independently comprise two or more lithium transition metal oxides.
  • one of the core or shell comprises only one lithium transition metal oxide, while the other comprises two or more lithium transition metal oxides.
  • the lithium transition metal oxide or oxides in the core and the shell may be the same, or they may be different or partially different.
  • the two or more lithium transition metal oxides are uniformly distributed over the core.
  • the two or more lithium transition metal oxides are not uniformly distributed over the core.
  • the cathode active material is not a core-shell composite.
  • each of the lithium transition metal oxides in the core and the shell is independently doped with a dopant selected from the group consisting of Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof.
  • the core and the shell each independently comprise two or more doped lithium transition metal oxides.
  • the two or more doped lithium transition metal oxides are uniformly distributed over the core and/or the shell. In certain embodiments, the two or more doped lithium transition metal oxides are not uniformly distributed over the core and/or the shell.
  • the cathode active material comprises or is a core-shell composite comprising a core comprising a lithium transition metal oxide and a shell comprising a transition metal oxide.
  • the lithium transition metal oxide is selected from the group consisting of Li 1+x Ni a Mn b Co c Al (1-a-b-c) O 2 , LiCoO 2 , LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 3 , LiCrO 2 , Li 4 Ti 5 O 12 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , LiCo a Ni b O 2 , LiMn a Ni b O 2 , and combinations thereof; wherein -0.2 ⁇ x ⁇ 0.2, 0 ⁇ a ⁇ 1, 0 ⁇ b ⁇ 1, 0 ⁇ c ⁇ 1, and a+b+c ⁇ 1.
  • x in the above general formula is independently selected from -0.2, -0.175, -0.15, -0.125, -0.1, -0.075, -0.05, -0.025, 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175 and 0.2; each a in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95 and 0.975; each b in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125,
  • each x, a, b and c in the above general formula independently has a 0.01 interval.
  • the transition metal oxide is selected from the group consisting of Fe 2 O 3 , MnO 2 , Al 2 O 3 , MgO, ZnO, TiO 2 , La 2 O 3 , CeO 2 , SnO 2 , ZrO 2 , RuO 2 , and combinations thereof.
  • the shell comprises a lithium transition metal oxide and a transition metal oxide.
  • the diameter of the core is from about 1 ⁇ m to about 15 ⁇ m, from about 3 ⁇ m to about 15 ⁇ m, from about 3 ⁇ m to about 10 ⁇ m, from about 5 ⁇ m to about 10 ⁇ m, from about 5 ⁇ m to about 45 ⁇ m, from about 5 ⁇ m to about 35 ⁇ m, from about 5 ⁇ m to about 25 ⁇ m, from about 10 ⁇ m to about 45 ⁇ m, from about 10 ⁇ m to about 40 ⁇ m, or from about 10 ⁇ m to about 35 ⁇ m, from about 10 ⁇ m to about 25 ⁇ m, from about 15 ⁇ m to about 45 ⁇ m, from about 15 ⁇ m to about 30 ⁇ m, from about 15 ⁇ m to about 25 ⁇ m, from about 20 ⁇ m to about 35 ⁇ m, or from about 20 ⁇ m to about 30 ⁇ m.
  • the thickness of the shell is from about 1 ⁇ m to about 45 ⁇ m, from about 1 ⁇ m to about 35 ⁇ m, from about 1 ⁇ m to about 25 ⁇ m, from about 1 ⁇ m to about 15 ⁇ m, from about 1 ⁇ m to about 10 ⁇ m, from about 1 ⁇ m to about 5 ⁇ m, from about 3 ⁇ m to about 15 ⁇ m, from about 3 ⁇ m to about 10 ⁇ m, from about 5 ⁇ m to about 10 ⁇ m, from about 10 ⁇ m to about 35 ⁇ m, from about 10 ⁇ m to about 20 ⁇ m, from about 15 ⁇ m to about 30 ⁇ m, from about 15 ⁇ m to about 25 ⁇ m, or from about 20 ⁇ m to about 35 ⁇ m.
  • the diameter or thickness ratio of the core and the shell are in the range of 15: 85 to 85: 15, 25: 75 to 75: 25, 30: 70 to 70: 30, or 40: 60 to 60: 40.
  • the volume or weight ratio of the core and the shell is 95: 5, 90: 10, 80: 20, 70: 30, 60: 40, 50: 50, 40: 60, or 30: 70.
  • the electrode active material is an anode active material, wherein the anode active material is selected the group consisting of natural graphite particulate, synthetic graphite particulate, hard carbon, soft carbon, mesocarbon microbeads (MCMB) , Sn particulate, SnO 2 , SnO, Li 4 Ti 5 O 12 particulate, Si particulate, Si-C composite particulate, and combinations thereof.
  • the anode active material is selected the group consisting of natural graphite particulate, synthetic graphite particulate, hard carbon, soft carbon, mesocarbon microbeads (MCMB) , Sn particulate, SnO 2 , SnO, Li 4 Ti 5 O 12 particulate, Si particulate, Si-C composite particulate, and combinations thereof.
  • the anode active material is doped with a metallic element or a nonmetal element.
  • the metallic element is selected from the group consisting of Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru and combinations thereof.
  • the nonmetal element is B, Si, Ge, N, P, F, S, Cl, I, Se and combinations thereof.
  • the anode active material comprises or is a core-shell composite having a core and shell structure, wherein the core and the shell each is independently selected from the group consisting of natural graphite particulate, synthetic graphite particulate, hard carbon, soft carbon, mesocarbon microbeads (MCMB) , Sn particulate, SnO 2 , SnO, Li 4 Ti 5 O 12 particulate, Si particulate, Si-C composite particulate, and combinations thereof.
  • MCMB mesocarbon microbeads
  • the core-shell composite comprises a core comprising a carbonaceous material and a shell coated on the carbonaceous material core.
  • the carbonaceous material is selected from the group consisting of soft carbon, hard carbon, natural graphite particulate, synthetic graphite particulate, mesocarbon microbeads, Kish graphite, pyrolytic carbon, mesophase pitches, mesophase pitch-based carbon fiber, and combinations thereof.
  • the shell is selected from the group consisting of natural graphite particulate, synthetic graphite particulate, hard carbon, soft carbon, mesocarbon microbeads (MCMB) , Sn particulate, SnO 2 , SnO, Li 4 Ti 5 O 12 particulate, Si particulate, Si-C composite particulate, and combinations thereof.
  • MCMB mesocarbon microbeads
  • the anode active material is not doped with a metallic element or a nonmetal element. In some embodiments, the anode active material is not doped with Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, B, Si, Ge, N, P, F, S, Cl, I, or Se.
  • the metal-containing material is selected from the group consisting of ceramic, metal, mischmetal or combinations thereof.
  • the ceramic is selected from the group consisting of AlCeO 3 , LiAlO 2 , MgAl 2 O 4 , Ce 0.63 Tb 0.37 MgAl 11 O 19 , Sr 0.95 Eu 0.02 Dy 0.03 Al 2 O 4 , Sr 3.84 Eu 0.06 Dy 0.10 Al 14 O 25 , BaFe 12 O 19 , CuFe 2 O 4 , CuZnFe 2 O 4 , LiFeO 2 , NiZnFe 4 O 4 , SrFe 12 O 19 , Y 3 Fe 5 O 12 , LiNbO 3 , KNbO 3 , Zn (NbO 3 ) 2 , Cu 2 Cr 2 O 5 , LiTaO 3 , NiCoO 2 , YBaCuO, BaZrO 3 , CaZrO 3 , PbZrO 3 , Li 2 ZrO 3 , Al 2 TiO 5 , Al 2 O 3 , BaTiO 3 , CaTiO 3 , Ca
  • the metal is selected from the group consisting of aluminium, bismuth, chromium, cobalt, copper, gold, iron, lead, magnesium, manganese, mercury, nickel, silver, titanium, tin, zinc, boron, phosphorous, sulphur, scandium, cadmium, molybdenum, tungsten, arsenic, beryllium, silicon, vanadium, cerium, zirconium, antimony or alloys thereof.
  • the mischmetal is selected from the group consisting of scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium or alloys thereof.
  • the electrode active material and the metal-containing material can be dissolved in the second suspension disclosed herein.
  • a first suspension comprises a combination of a polymeric binder, an electrode active material and an aqueous solvent, a combination of a polymeric binder, a metal-containing material and an aqueous solvent or a combination of a polymeric binder, an electrode active material, a metal-containing material and an aqueous solvent
  • the electrode active material and/or the metal-containing material begin to dissolve whereas the polymeric binder is precipitated.
  • any previously undissolved polymeric binder within the clusters of electrode active material or metal-containing material could be exposed and thus be precipitated in the second suspension. This allows separation of the polymeric binder from the remaining of the second suspension.
  • the electrode layer may additionally comprise other additives for enhancing electrode properties.
  • the additives may include conductive agents, surfactants, dispersants and flexibility enhancement additives.
  • the additives do not dissolve in an aqueous solvent and/or the second suspension disclosed herein.
  • the first suspension may further comprise conductive agents, surfactants, dispersants, flexibility enhancement additives or combinations thereof.
  • the electrode layer further comprises a conductive agent.
  • the first suspension further comprises a conductive agent.
  • the conductive agent is for enhancing the electrically-conducting property of an electrode. Any suitable material can act as the conductive agent.
  • the conductive agent is a carbonaceous material. Some non-limiting examples include carbon, carbon black, graphite, expanded graphite, graphene, graphene nanoplatelets, carbon fibers, carbon nano-fibers, graphitized carbon flake, carbon tubes, activated carbon, Super P, 0-dimensional KS6, 1-dimensional vapor grown carbon fibers (VGCF) , mesoporous carbon and combinations thereof.
  • the conductive agent does not dissolve in an aqueous solvent and/or the second suspension disclosed herein.
  • a first suspension comprises a combination of a polymeric binder, an electrode active material, a conductive agent and an aqueous solvent, a combination of a polymeric binder, a metal-containing material, a conductive agent and an aqueous solvent or a combination of a polymeric binder, an electrode active material, a metal-containing material, a conductive agent and an aqueous solvent
  • the electrode active material and/or the metal-containing material begin to dissolve in the second suspension, the conductive agent remains as solids and the polymeric binder is precipitated.
  • the precipitation agent in the case where a polymer, an electrode layer and an aqueous solvent are involved in the system, can be mixed with an aqueous solvent to form a first suspension. Thereafter, a second suspension can be formed by adding an electrode layer into the first suspension. In other embodiments, in the case where a polymer, an electrode layer and an aqueous solvent are involved in the system, the electrode layer and the precipitation agent can be directly added into an aqueous solvent to form a first suspension.
  • the sequence of addition of the precipitation agent, the electrode layer and the aqueous solvent as disclosed in the method of the present invention has negligible effect on the variations in the polymer recovery rate, i.e., the polymer can still be precipitated effectively with a high polymer recovery rate of over 98%regardless of the sequence of addition of the precipitation agent, the electrode layer and the aqueous solvent in the method disclosed herein.
  • the polymeric binder applied in the present invention exhibits exceptionally strong binding capability.
  • One way in assessing the strength of the adhesion property of a polymeric binder is via the adhesive strength between a polymeric binder and a current collector. It is important for the polymeric binder to have good adhesive strength to the current collector as it promotes the binding force of the electrode layer to the current collector in the making of battery electrode, prevents separation and enhances the mechanical stability of the electrode.
  • the adhesive strength between the polymeric binder and the current collector is from about 2 N/cm to about 6 N/cm, from about 2 N/cm to about 5.8 N/cm, from about 2 N/cm to about 5.6 N/cm, from about 2 N/cm to about 5.4 N/cm, from about 2 N/cm to about 5.2 N/cm, from about 2 N/cm to about 5 N/cm, from about 2 N/cm to about 4.8 N/cm, from about 2 N/cm to about 4.6 N/cm, from about 2 N/cm to about 4.4 N/cm, from about 2 N/cm to about 4.2 N/cm, from about 2 N/cm to about 4 N/cm, from about 2 N/cm to about 3.9 N/cm, from about 2 N/cm to about 3.8 N/cm, from about 2 N/cm to about 3.7 N/cm, from about 2 N/cm to about 3.6 N/cm
  • the adhesive strength between the polymeric binder and the current collector is less than 6 N/cm, less than 5.8 N/cm, less than 5.6 N/cm, less than 5.4 N/cm, less than 5.2 N/cm, less than 5 N/cm, less than 4.8 N/cm, less than 4.6 N/cm, less than 4.4 N/cm, less than 4.2 N/cm, less than less than 4 N/cm, less than 3.9 N/cm, less than 3.8 N/cm, less than 3.7 N/cm, less than 3.6 N/cm, less than 3.5 N/cm, less than 3.4 N/cm, less than 3.3 N/cm, less than 3.2 N/cm, less than 3.1 N/cm, less than 3 N/cm, less than 2.9 N/cm, less than 2.8 N/cm, less than 2.7 N/cm, less than 2.6 N/cm, less than 2.5 N/cm, less than 2.4 N
  • the adhesive strength between the polymeric binder and the current collector is more than 2 N/cm, more than 2.1 N/cm, more than 2.2 N/cm, more than 2.3 N/cm, more than 2.4 N/cm, more than 2.5 N/cm, more than 2.6 N/cm, more than 2.7 N/cm, more than 2.8 N/cm, more than 2.9 N/cm, more than 3 N/cm, more than 3.1 N/cm, more than 3.2 N/cm, more than 3.3 N/cm, more than 3.4 N/cm, more than 3.5 N/cm, more than 3.6 N/cm, more than 3.7 N/cm, more than 3.8 N/cm, more than 3.9 N/cm, more than 4 N/cm, more than 4.2 N/cm, more than 4.4 N/cm, more than 4.6 N/cm, more than 4.8 N/cm, more than 5 N/cm, more than 5.2 N/cm
  • the polymeric binder applied in the present invention allows the exhibition of strong adhesion of the electrode layer to the current collector in an electrode. It is important for the electrode layer to have good peeling strength to the current collector as this would greatly influence the mechanical stability of the electrodes and the cyclability of the battery. Therefore, the electrodes should have sufficient peeling strength to withstand the rigors of battery manufacture.
  • the peeling strength between the current collector and the electrode layer is in the range from about 1.0 N/cm to about 8.0 N/cm, from about 1.0 N/cm to about 6.0 N/cm, from about 1.0 N/cm to about 5.0 N/cm, from about 1.0 N/cm to about 4.0 N/cm, from about 1.0 N/cm to about 3.0 N/cm, from about 1.0 N/cm to about 2.5 N/cm, from about 1.0 N/cm to about 2.0 N/cm, from about 1.2 N/cm to about 3.0 N/cm, from about 1.2 N/cm to about 2.5 N/cm, from about 1.2 N/cm to about 2.0 N/cm, from about 1.5 N/cm to about 3.0 N/cm, from about 1.5 N/cm to about 2.5 N/cm, from about 1.5 N/cm to about 2.0 N/cm from about 1.8 N/cm to about 3.0 N/cm, from about 1.8 N/cm to about
  • the peeling strength between the current collector and the electrode layer is 1.0 N/cm or more, 1.2 N/cm or more, 1.5 N/cm or more, 2.0 N/cm or more, 2.2 N/cm or more, 2.5 N/cm or more, 3.0 N/cm or more, 3.5 N/cm or more, 4.5 N/cm or more, 5.0 N/cm or more, 5.5 N/cm or more, 6.0 N/cm or more, 6.5 N/cm or more, 7.0 N/cm or more or 7.5 N/cm or more.
  • the peeling strength between the current collector and the electrode layer is less than 8.0 N/cm, less than 7.5 N/cm, less than 7.0 N/cm, less than 6.5 N/cm, less than 6.0 N/cm, less than 5.5 N/cm, less than 5.0 N/cm, less than 4.5 N/cm, less than 4.0 N/cm, less than 3.5 N/cm, less than 3.0 N/cm, less than 2.8 N/cm, less than 2.5 N/cm, less than 2.2 N/cm, less than 2.0 N/cm, less than 1.8 N/cm, or less than 1.5 N/cm.
  • Figure 10 is a flow chart of an embodiment illustrating the steps of method 1000 for precipitating a polymeric binder as disclosed herein and its subsequent further processing for extraction of the polymer.
  • the remaining of the second suspension comprising the aqueous solvent, the dissolved precipitation agent and the dissolved electrode active material may be subjected to additional separation and/or extraction process to further extract the electrode active material and the precipitation agent contained within.
  • the recovered polymeric binder could be subjected to neutralization to be further reused in the subsequent battery manufacturing process. This allows the formation of a closed-loop recovery process where materials are repeatedly recycled and reused, and continually engage in a loop arrangement, which helps create a circular economy.
  • the present invention provides a simple method that can be used to precipitate polymeric binder of different compositions.
  • the separation of the polymeric binder and the other electrode layer constituents constitutes a vital step in the recycling of batteries
  • the method disclosed herein offers a technical solution in fulfilling the demand in battery recycling.
  • the method of the present invention circumvents both complex separation process and contamination of the polymeric binder, enables an excellent materials recovery (i.e. high polymer recovery rate) and considerably reduces the time required to precipitate the polymeric binder.
  • the pH values of the second suspension were measured by an electrode-type pH meter (ION 2700, Eutech Instruments) .
  • the polymer recovery rate refers to the proportion of the weight of the recovered polymer, based on the initial weight of polymer present in the first suspension before the addition of a precipitation agent.
  • the adhesive strengths of the dried polymeric binder layers were measured by a tensile testing machine (DZ-106A, obtained from Dongguan Zonhow Test Equipment Co. Ltd., China) . This test measures the average force required to peel a polymeric binder layer from the current collector at 180° angle in Newtons.
  • the mean roughness depth (R z ) of the current collector is 2 ⁇ m.
  • the polymeric binder was coated on the current collector and dried to obtain a polymeric binder layer of thickness 10 ⁇ m to 12 ⁇ m. The coated current collector was then placed in an environment of constant temperature of 25 °C and humidity of 50%to 60%for 30 minutes.
  • a strip of adhesion tape (3M; US; model no.
  • the polymeric binder strip was clipped onto the testing machine and the tape was folded back on itself at 180 degrees, and placed in a moveable jaw and pulled at room temperature and a peel rate of 300 mm per minute. The maximum stripping force measured was taken as the adhesive strength. Measurements were repeated three times to find the average value.
  • the peeling strengths of the dried electrode layers were measured by a tensile testing machine (DZ-106A, obtained from Dongguan Zonhow Test Equipment Co. Ltd., China) . This test measures the average force required to peel an electrode layer from the current collector at 180° angle in Newtons.
  • the mean roughness depth (R z ) of the current collector is 2 ⁇ m.
  • a strip of adhesion tape (3M; US; model no. 810) with a width of 18 mm and a length of 20 mm was attached onto the surface of the cathode electrode layer.
  • the cathode strip was clipped onto the testing machine and the tape was folded back on itself at 180 degrees, and placed in a moveable jaw and pulled at room temperature and a peel rate of 200 mm per minute.
  • the maximum stripping force measured was taken as the peeling strength. Measurements were repeated three times to find the average value.
  • AM acrylamide
  • 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; obtained from Aladdin Industries Corporation, China) was dissolved in 3 g of DI water and 0.0075 g of reducing agent (sodium bisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of DI water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added into the fourth mixture. The combination of ingredients was stirred at 200 rpm for 24 h at 55 °C to obtain a fifth mixture.
  • APS ammonium persulfate
  • reducing agent sodium bisulfite
  • the 1 M sulphuric acid solution was added into the first suspension to form a second suspension of pH 4.24.
  • the second suspension was stirred at 200 rpm for 10 mins at 25 °C.
  • the polymer was then precipitated.
  • the processed second suspension was removed by passing through a filter paper to recover the precipitated polymer.
  • the recovered polymer was dried in an oven for 5 hours at 80 °C under atmospheric pressure and obtained a polymer recovery rate of 98.58%. The dried polymer could then be further reused.
  • the polymer recovery rate and pH of the second suspension were measured and is shown in Table 1 below.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 45.04 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.60 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.52 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.08 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.68 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.24 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.53 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.09 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.59 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.15 g.
  • the fourth mixture was heated up to 60 °C and stirred at 60 rpm for 45 mins.
  • 0.23 g of APS was dissolved in 82.68 g of DI water and 0.04 g of sodium bisulfite was dissolved in 17.22 g of DI water. 17.26 g of sodium bisulfite solution was added into the fourth mixture and the combination of ingredients was stirred for 10 minutes.
  • 82.91 g of APS solution was added into the mixture dropwise for 3 h to form a fifth mixture.
  • the fifth mixture was further stirred at 200 rpm for 20 h at 65 °C.
  • the temperature of the fifth mixture was lowered to 40 °C and 5.62 g of lithium hydroxide (dissolved in 116.64 g of DI water) was added into the fifth mixture to adjust pH to 7.44 to form the sixth mixture.
  • the temperature of the sixth mixture was lowered to 30 °C and the polymer was furnished by filtration using 200 ⁇ m nylon mesh.
  • the solid content of the polymer was 14.93 wt. %.
  • the adhesive strength between the polymer and the current collector was 3.41 N/cm.
  • the components of the polymer of Example 7 and their respective proportions are shown in Table 1 below.
  • the 1 M sulphuric acid solution was added into the first suspension to form a second suspension of pH 3.99.
  • the second suspension was stirred at 200 rpm for 10 mins at 25 °C.
  • the polymer was then precipitated.
  • the processed second suspension was removed by passing through a filter paper to recover the precipitated polymer.
  • the recovered polymer was dried in an oven for 5 hours at 80 °C under atmospheric pressure and obtained a polymer recovery rate of 98.73%. The dried polymer could then be further reused.
  • the polymer recovery rate and pH of the second suspension were measured and is shown in Table 1 below.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.10 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.45 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 47.07 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.42 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.22 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.57 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.46 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.81 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.78 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.13 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.63 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.19 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.32 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.67 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.76 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.32 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.36 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.71 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.69 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.25 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.49 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.84 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.73 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.29 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.25 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.60 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that in the preparation of the polymer, 36.04 g of AA was replaced with 2-ethylacrylic acid of the same weight in the preparation of the second mixture; and in the formation of the first suspension, 5.56 g of polymer was added into 44.58 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.14 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that in the preparation of the polymer, 36.04 g of AA was replaced with crotonic acid of the same weight in the preparation of the second mixture; and in the formation of the first suspension, 5.56 g of polymer was added into 44.67 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.23 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that in the preparation of the polymer, 31.54 g of AA was replaced with 2-ethylacrylic acid of the same weight in the preparation of the second mixture; and in the formation of the first suspension, 3.35 g of polymer was added into 46.48 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.83 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that in the preparation of the polymer, 31.54 g of AA was replaced with crotonic acid of the same weight in the preparation of the second mixture; and in the formation of the first suspension, 3.35 g of polymer was added into 46.44 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.79 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.63 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.19 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.56 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.12 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.47 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.82 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.40 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.75 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that 5.56 g of polymer was added into 44.68 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.24 g.
  • Preparation of first suspension was performed in the same manner as in Example 7, except that 3.35 g of polymer was added into 46.53 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 49.88 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that in the preparation of the polymer, polyacrylic acid (PAA) was used as the polymer; and in the formation of the first suspension, 5.56 g of PAA was added into 44.97 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.53 g.
  • the solid content of the first suspension was 1.00 wt. %.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that in the preparation of the polymer, 61.20 g of AA was added in the preparation of the second mixture, no AM was added in the preparation of the third mixture and 6.80 g of AN was added in the preparation of the fourth mixture; and in the formation of the first suspension, 5.56 g of polymer was added into 44.88 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.44 g.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that in the preparation of the polymer, polyacrylamide (PAM) was used as the polymer; and in the formation of the first suspension, 5.56 g of PAM was added into 44.47 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.03 g.
  • the solid content of the first suspension was 1.00 wt. %.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that in the preparation of the polymer, carboxymethyl cellulose (CMC; BSH-12, DKS Co. Ltd., Japan) was used as the polymer; and in the formation of the first suspension, 0.50 g of CMC was added into 49.50 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.00 g.
  • the solid content of the first suspension was 1.00 wt. %.
  • Preparation of first suspension was performed in the same manner as in Example 1, except that in the preparation of the polymer, styrene butadiene rubber (SBR, 45 wt. %in water; AL-2001, NIPPON A&L INC., Japan) was used as the polymer; and in the formation of the first suspension, 1.11 g of SBR was added into 48.89 g of distilled water and the mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 50.00 g. The solid content of the first suspension was 1.00 wt. %.
  • SBR styrene butadiene rubber
  • a first admixture was prepared by mixing 9.32 g of polymeric binder (14.93 wt. %solid content) and 19.70 g of cathode active material (NMC532; obtained from Shandong Tianjiao New Energy Co., Ltd, China) at 25 °C while stirring with an overhead stirrer for about 15 minutes. Then, the first admixture was dried to form a conglomerate by an electrically heated oven at 70 °C. The drying time was about 45 minutes.
  • the 3 M sulphuric acid solution was added into the first suspension to form a second suspension of pH 0.89.
  • the second suspension was stirred at 200 rpm for 2 hours at 90 °C.
  • the prolonged period of stirring time and the elevation in temperature were intended for to achieve dissolution of the NMC532 in a more efficient manner.
  • the polymeric binder was then precipitated and NMC532 dissolved in the second suspension.
  • the processed second suspension was removed by passing through a filter paper to recover the precipitated polymeric binder.
  • the recovered polymeric binder was dried in an oven for 5 hours at 80 °C under atmospheric pressure and obtained a polymer recovery rate of 99.10%.
  • the dried polymeric binder could then be further reused.
  • the polymer recovery rate and pH of the second suspension were measured and is shown in Table 2 below.
  • Preparation of first suspension was performed in the same manner as in Example 25, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 9.24 g of polymeric binder (14.93 wt. %solid content) and 22.7 g of Al 2 O 3 at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • Preparation of first suspension was performed in the same manner as in Example 25, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 6.59 g of polymeric binder (14.93 wt. %solid content) and 17.99 g of Al at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • Preparation of first suspension was performed in the same manner as in Example 25, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 9.32 g of polymeric binder (14.93 wt. %solid content) and 19.70 g of LCO at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • Preparation of first suspension was performed in the same manner as in Example 25, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 9.32 g of polymeric binder (14.93 wt. %solid content) and 19.70 g of LFP at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • a first admixture was prepared by mixing 11.23 g of polymeric binder (9.00 wt. %solid content) and 19.20 g of cathode active material (NMC532; obtained from Shandong Tianjiao New Energy Co., Ltd, China) at 25 °C while stirring with an overhead stirrer for about 15 minutes. Then, the first admixture was dried to form a conglomerate by an electrically heated oven at 70 °C. The drying time was about 45 minutes.
  • the 3 M sulphuric acid solution was added into the first suspension to form a second suspension of pH 1.13.
  • the second suspension was stirred at 200 rpm for 2 hours at 90 °C.
  • the polymeric binder was then precipitated and NMC532 dissolved in the second suspension.
  • the processed second suspension was removed by passing through a filter paper to recover the precipitated polymeric binder.
  • the recovered polymeric binder was dried in an oven for 5 hours at 80 °C under atmospheric pressure and obtained a polymer recovery rate of 99.21%.
  • the dried polymeric binder could then be further reused.
  • the polymer recovery rate and pH of the second suspension were measured and is shown in Table 2 below.
  • Preparation of first suspension was performed in the same manner as in Example 31, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 11.23 g of polymeric binder (9.00 wt. %solid content) and 22.7 g of Al 2 O 3 at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • Preparation of first suspension was performed in the same manner as in Example 31, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 11.23 g of polymeric binder (9.00 wt. %solid content) and 17.99 g of Al at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • Preparation of first suspension was performed in the same manner as in Example 31, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 11.23 g of polymeric binder (9.00 wt. %solid content) and 19.20 g of LCO at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • Preparation of first suspension was performed in the same manner as in Example 31, except that in the preparation of the conglomerate, a first admixture was prepared by mixing 11.23 g of polymeric binder (9.00 wt. %solid content) and 19.20 g of LFP at 25 °C while stirring with an overhead stirrer for about 15 minutes.
  • a cathode layer was obtained from a used lithium-ion battery.
  • the polymeric binder within the cathode layer was prepared in the same manner as in Example 25. 4.48 g of the crushed cathode layer was added into a round-bottom flask containing 60 g of aqueous solvent (distilled water) . The mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 64.48 g.
  • the 3 M sulphuric acid solution was added into the first suspension to form a second suspension of pH 1.22.
  • the second suspension was stirred at 200 rpm for 2 hours at 90 °C.
  • the prolonged period of stirring time and the elevation in temperature were intended for to achieve dissolution of the NMC532 in a more efficient manner.
  • the polymeric binder was then precipitated and NMC532 dissolved in the second suspension.
  • the processed second suspension was passed through a filter paper to recover the conductive agent and the precipitated polymeric binder.
  • the remaining processed second suspension can be subjected to additional extraction process to further extract the electrode active material and the precipitation agent contained within.
  • the recovered polymeric binder was dried in an oven for 5 hours at 80 °C under atmospheric pressure and obtained a polymer recovery rate of 99.32%.
  • a cathode layer was obtained from a used lithium-ion battery.
  • the polymeric binder within the cathode layer was prepared in the same manner as in Example 31. 4.38 g of the crushed cathode layer was added into a round-bottom flask containing 60 g of aqueous solvent (distilled water) . The mixture was stirred at 80 rpm for 10 mins to obtain a first suspension of 64.38 g.
  • the 3 M sulphuric acid solution was added into the first suspension to form a second suspension of pH 1.36.
  • the second suspension was stirred at 200 rpm for 2 hours at 90 °C.
  • the prolonged period of stirring time and the elevation in temperature were intended for to achieve dissolution of the NMC532 in a more efficient manner.
  • the polymeric binder was then precipitated and NMC532 dissolved in the second suspension.
  • the processed second suspension was passed through a filter paper to recover the conductive agent and the precipitated polymeric binder.
  • the remaining processed second suspension can be subjected to additional extraction process to further extract the electrode active material and the precipitation agent contained within.
  • the recovered polymeric binder was dried in an oven for 5 hours at 80 °C under atmospheric pressure and obtained a polymer recovery rate of 99.01%.

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Abstract

L'invention concerne un procédé de précipitation d'un polymère par l'ajout d'un agent de précipitation dans une première suspension pour former une seconde suspension ; la première suspension comprenant un polymère et un solvant aqueux ; et le polymère comprenant un copolymère comprenant une unité structurale dérivée d'un monomère contenant un groupe acide et une unité structurale dérivée d'un monomère contenant un groupe hydrophobe. Le procédé de précipitation d'un polymère selon l'invention est mis au point pour initier la rupture et/ou la cassure de liaison entre le polymère et le solvant aqueux dans la seconde suspension. Ceci s'accompagne de la transformation structurale du polymère entraînée par les interactions intermoléculaires et intramoléculaires des chaînes polymères qui provoque la précipitation du polymère. Le procédé contourne à la fois le processus de séparation complexe et la contamination du polymère, permet une excellente récupération de matériaux et permet de réaliser la précipitation du polymère dans une courte période de temps. L'invention concerne également une application du procédé de précipitation d'un liant polymère dans une électrode de batterie.
PCT/CN2021/076466 2020-06-17 2021-02-10 Procédé de précipitation de polymère WO2021253849A1 (fr)

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AU2021291911A AU2021291911A1 (en) 2020-06-17 2021-02-10 Method for polymer precipitation
CA3183237A CA3183237A1 (fr) 2020-06-17 2021-02-10 Procede de precipitation de polymere
EP21825136.1A EP4169095A4 (fr) 2020-06-17 2021-02-10 Procédé de précipitation de polymère
KR1020237001858A KR20230028398A (ko) 2020-06-17 2021-02-10 폴리머 침전 방법
US17/914,367 US20230105056A1 (en) 2020-06-17 2021-02-10 Method for polymer precipitation
CN202180007279.4A CN114846654B (zh) 2020-06-17 2021-02-10 用于使聚合物沉淀的方法
JP2022578586A JP2023530012A (ja) 2020-06-17 2021-02-10 複合材剥離方法
KR1020237002049A KR20230027207A (ko) 2020-06-17 2021-06-16 전지 전극 재활용 방법
PCT/CN2021/100365 WO2021254393A1 (fr) 2020-06-17 2021-06-16 Procédé de recyclage d'électrodes de batterie
US18/007,753 US20230299372A1 (en) 2020-06-17 2021-06-16 Method for recycling battery electrodes
EP21826301.0A EP4169109A4 (fr) 2020-06-17 2021-06-16 Procédé de recyclage d'électrodes de batterie
CA3183241A CA3183241A1 (fr) 2020-06-17 2021-06-16 Procede de recyclage d'electrodes de batterie
JP2022577316A JP2023529986A (ja) 2020-06-17 2021-06-16 電池電極のリサイクル方法
AU2021290702A AU2021290702A1 (en) 2020-06-17 2021-06-16 Method for recycling battery electrodes
CN202180041284.7A CN115885408A (zh) 2020-06-17 2021-06-16 回收电池电极的方法
TW110121970A TW202210530A (zh) 2020-06-17 2021-06-16 用於使聚合物沉澱的方法
TW110122185A TW202220271A (zh) 2020-06-17 2021-06-17 回收電池電極的方法

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PCT/CN2020/096672 WO2021253302A1 (fr) 2020-06-17 2020-06-17 Composition conductrice pour batterie secondaire
PCT/CN2020/110065 WO2021253615A1 (fr) 2020-06-17 2020-08-19 Composition de liant pour batterie secondaire
CNPCT/CN2020/110065 2020-08-19
PCT/CN2020/117789 WO2021253675A1 (fr) 2020-06-17 2020-09-25 Composition de liant pour batterie secondaire
CNPCT/CN2020/117789 2020-09-25
PCT/CN2020/139555 WO2021253787A1 (fr) 2020-06-17 2020-12-25 Procédé de délaminage de composite
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