Classifications

• • 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
  • C08F220/52—Amides or imides
  • C08F220/54—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
  • C08F220/56—Acrylamide; Methacrylamide
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/18—Reinforcing agents
• • 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
  • C08F220/10—Esters
  • C08F220/34—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate
• • 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
  • C08F220/52—Amides or imides
  • C08F220/54—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
  • C08F220/60—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide containing nitrogen in addition to the carbonamido nitrogen
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/37—Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
  • D21H17/375—Poly(meth)acrylamide
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
  • D21H17/45—Nitrogen-containing groups

Definitions

• the present invention relates to materials and methods for the preparation of high molecular weight compact structured water-soluble polymers. These polymers are particularly useful in the paper making industry.
• Structured polymers and copolymers have attracted considerable attention over the past decades due to new and improved properties of the resulting polymers.
• the term “structured” as used herein with respect to synthetic polymers is intended to designate non-linear polymers.
• Polymers such as acrylamide polymers have been used throughout the papermaking process as dry strength agents, drainage agents, retention aids, coagulants, dispersants, etc. Dry strength is an important property, which must be met at some minimum level to meet the end use for paper and paperboard products.
• Acrylamide containing polymers are well known in the paper industry to provide dry strength. Linear acrylamide polymers having a weight-average molecular weight range from about 50,000 to somewhat greater than 5,000,000 have conventionally been used as dry strength agents.
• acrylamide based commercial examples include acrylic acid (AA)/acrylamide (AcAm) copolymer, glyoxalated diallyldimethylammonium chloride (DADMAC)/AcAm, and an amphoteric polymer composed of AcAm/itaconic acid/dimethylammoniumethylmethacryl ate (DMAEM)/dimethylammoniumethylacrylate benzyl chloride quat (DMAEA BCQ).
• DMAEM glyoxalated diallyldimethylammonium chloride
• DMAEM glyoxalated diallyldimethylammonium chloride
• DMAEM glyoxalated diallyldimethylammonium chloride
• DMAEM glyoxalated diallyldimethylammonium chloride
• DMAEM glyoxalated diallyldimethylammonium chloride
• DMAEM glyoxalated diallyldimethylammonium chloride
• a water-soluble structured polymer having a weight-average molecular weight of from about 100,000 to about 5,000,000 is provided.
• This polymer is obtained by polymerizing one or more amine-containing unsaturated monomers or polymers.
• the polymerization reaction is a reaction mixture of at least one of amine-containing groups comprising ethylenically unsaturated primary, secondary, or tertiary amines and mixtures thereof, a pre-formed polymer comprising a secondary or tertiary amine; and optionally, at least one of acrylamide or methacrylamide.
• the resulting structured polymer has an apparent conformation coefficient of less than or equal to about 0.40 in sodium nitrate solution, measured at a pH of about 3 and a greater than or equal to about 80% solubility as determined by SEC/MALLS techniques.
• a number of water-soluble structured polymers are derived from the polymerization reaction of monomers comprising one or more amine-containing groups.
• a high molecular weight water-soluble structured polymer is obtained from polymerizing one or more ethylenically unsaturated amine monomers.
• a non-acrylamide based terpolymer was obtained from copolymer components of monoallylamine (MAA), diallyamine (DAA), and triallylamine (TAA) and mixtures thereof.
• An acrylamide based high molecular weight water-soluble structured polymer is provided from polymerization of acrylamide and one or more of ethylenically unsaturated amine monomers.
• a reaction mixture may contain acrylamide (AcAm) and dimethylaminoethylmethacrylate (DMAEM) resulting in structured AcAm/DMAEM copolymers.
• Pre-formed polymers include, but not limited to, poly(amidoamine) or diallyldimethylammonium chloride (DADMAC)/dimethylaminopropyl methacrylamide (DMAPMA) copolymer.
• DADMAC diallyldimethylammonium chloride
• DMAPMA dimethylaminopropyl methacrylamide
• the structured polymers are useful as improved dry strength additive for papermaking process.
• the characteristics of dry strength structured polymers are identified by:
• Dry strength agents include, but are not limited to, co-monomers of (a) acrylamide; and (b) one or more ethylenically unsaturated monomers.
• Monomers including but not limited to dimethylaminoethylmethacrylate (DMAEM), dimethylaminoethylacrylate (DMAEA), dimethylaminopropyl methacrylamide (DMAPMA), and dimethylaminopropyl acrylamide (DMAPAA) and salts thereof.
• “About” is equal to, greater or less than 2 digital units on either side of the reference number.
• “Structured polymer” refers to a compact non-linear polymer with controlled branching as prepared by the polymerization process disclosed herein, the structure of which includes any deviation from linearity in the backbone polymer chain.
• An ethylenically unsaturated primary, secondary, or tertiary amine refers to amine containing compounds having carbon-carbon double bonds that are reactive towards free radical polymerization.
• “Monomer” refers to a polymerizable allylic, vinylic or acrylic compound.
• a pre-formed polymer comprising a secondary or tertiary amine is a polymer backbone containing amine groups.
• Weight-average molecular weight refers to the molecular weight average of polymer determined by static light scattering measurement, specifically by Size-Exclusion-Chromatography/Multi-Angle-Laser-Light-Scattering (SEC/MALLS) technique.
• the instant structured polymer has a weight-average molecular weight of from about 100,000 to about 5,000,000.
• “Apparent conformation coefficient” is defined by the slope of the double logarithmic plot (root-mean-square-radius versus molecular weight of polymer) obtained from the ASTRA software (Wyatt Technology), specifically the top 20% of molecular weight distribution of polymer eluted from SEC columns is calculated.
• SEC Size-Exclusion-Chromatography that is a chromatography technique for polymer separation based on hydrodynamic volume of polymer.
• “MALLS” refers to Multi-Angle-Laser-Light-Scattering instrument (DAWN DSP-F) provided by Wyatt Technology
• “Improved dry strength additive” refers to the compact structured acrylamide polymer preferably containing acrylamide and/or methacrylamide in a proportion of 50 mole % or more, preferably 75-99 mole %, and especially 85-95 mole % which when added to the papermaking process increases dry strength by about 5%.
• Batch addition refers to a chemical addition process in which all the reaction components are added to the reactor before the reaction commences and then held under controlled conditions until the desired endpoint is reached.
• “Semi-batch” refers to as a chemical process in which one or more of the reaction components are added (in part or in whole) after the reaction commences.
• a “semi-batch addition” refers to the reaction component that is added over the course of the reaction.
• Oxidant refers to polymerization initiators including, but not limited to, persulfate and peroxide types, ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, tert-butylhydroperoxide benzoyl peroxide and tert-butyl peroxide.
• One or more primary, secondary or tertiary amine-containing monomers provide the structured polymers of the invention.
• monomers providing structured polymers include amines such as N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl methacrylamide, and N,N-dimethylaminopropylacrylamide, vinylamine, monoallylamine, (MAA) diallylamine and triallylamine and salts thereof.
• MAA diallylamine and triallylamine and salts thereof.
• the ethylenically unsaturated monomers employed in this invention may further include anionic, non-ionic, cationic, hydrophobic and hydrophilic types.
• Exemplary anionic monomers include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid and fumaric acid, and salts thereof; and vinylsulfonic acid, styrenesulfonic acid and acrylamidomethylpropanesulfonic acid, and salts thereof.
• non-ionic monomers include, but are not limited to, acrylamide, methacrylamide, N-vinylmethylacetamide, N-vinyl methyl formamide, vinyl formamide, vinyl acetate, vinyl pyrrolidone, methyl methacrylate, methacrylic esters, other acrylic or ethylenically unsaturated esters, styrene, and acrylonitrile.
• Illustrative examples of cationic monomers include quaternary amines salts such as N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl methacrylamide, and N,N-dimethylaminopropylacrylamide; and salts thereof (including quaternary salts).
• Examples of quaternary salts include dimethyldiallyammonium chloride and dimethyl aminoethyl acrylate methyl chloride quat.
• Exemplary hydrophobic monomers include N-alkyl (meth)acrylamide derivatives such as N,N-di-n-propylacrylamide, N-n-butylacrylamide, N-n-hexylacrylamide, N-n-hexylmethacrylamide, N-n-octylacrylamide, N-n-octylmethacrylamide, N-tert-octylacrylamide, N-dodecylacrylamide, and N-n-dodecylmethacylamide; N-(.omega.-glycidoxyalkyl) (meth)acrylamide derivatives such as N,N-diglycidylacrylamide, N,N-diglycidylmethacrylamide, N-(4-glycidoxybutyl)acrylamide, N-(4-glycidoxybutyl)methacrylamide, N-(5-glycidoxypentyl)acrylamide, and N(6-glycidoxyhex
• hydrophilic monomers include acetoneacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-ethylmethacrylamide, N-ethylacrylamide, N,N-diethylacrylamide, N-propylacrylamide, N-acryloylpyrrolidine, N-acryloylpiperidine, N-acryloylmorpholine, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, various methoxypolyethylene glycol (meth)acrylates, and N-vinyl-2-pyrrolidone.
• One or more of the above monomers may be used in the process for preparing the polymer of this invention.
• one acrylamide based monomer is used as monomer to prepare a water soluble structured polymer.
• a cationic monomer reaction mixture may contain acrylamide and dialkylaminoalkyl acrylate (as acid salt or quaternary salt) with dialkylaminoalkyl acrylate.
• An anionic monomer containing system can include acrylamide and acrylic acid monomer along with amine monomer needed to provide structure.
• the structured polymers of this invention exhibit a high molecular weight, a compact solution structure, and a high water-solubility due to the introduction of branches accomplished by the unique polymerization process.
• the advantages of the instant structured polymer of this invention are reflected in the apparent conformation coefficient, solubility and high molecular weight as determined by SEC/MALLS technique.
• a low value of the apparent conformation coefficient is indicative of 3-dimensional structuring while the good polymer recovery indicates that the structuring has not led to gel-like structures, which are less active.
• the apparent conformation coefficient is determined from SEC/MALLS measurements using the top 20% of the molecular weight distribution.
• the slope of the conformation plot defines the apparent conformation coefficient and differentiates structured polymers from linear polymers.
• the ability of the polymers to elute from SEC column is indicative of polymer solubility in dilute solution.
• Polymers structured through too much cross-linking or branching have a tendency to form insoluble fractions, and these fractions do not pass through the SEC column under the conditions.
• the specialized polymerization conditions employed does not introduce a crosslinking agent to produce the polymers of the instant invention, and this is thought to allow the polymers to display high water-solubility along with a high molecular weight, compact structure.
• the instantly claimed structured polymers are characterized by an apparent conformation coefficient of less than or equal to about 0.4 and concurrent solubility greater than or equal to about 80% as measured by SEC/MALLS technique. Exemplary apparent conformation coefficients less than about 0.4 or less with about greater than 90% are exhibited by the majority of the resulting polymers.
• a structured AcAm/DMAEM (90/10 mole ratio) copolymer exhibits an apparent conformation coefficient of about 0.3, 100% recovery, 1,000,000 weight-average molecular weight as determined by SEC/MALLS technique.
• Acrylamide copolymers were polymerized with DMAEM and DMAPMA under conditions expected to provide branching from alkyl group attached to the amine.
• Illustrative structured cationic copolymers AcAm/DMAEM (90/10), AcAm/DMAPMA (90/10), DMAPAA/AcAm/MAA(monoallyl amine) and DMAPMA/DMAPAA/AcAm/MAA exhibited apparent conformation coefficients less than about 0.4 and greater than 90% SEC recovery.
• SEC size exclusion chromatography/multi-angle laser light scattering
• SEC/MALLS size exclusion chromatography
• MALLS multi-angle laser light scattering detector
• OPTILAP DSP interferometric refractometer
• the aqueous mobile phase contained 0.1 molar sodium nitrate, phosphate buffer solution (pH 3) and a small amount of sodium azide.
• Data collection and analysis were performed with ASTRA software from Wyatt Technology. A Debye model and a 3 rd order detector fit method were employed in data analysis.
• An apparent conformation coefficient is defined by the slope of the double logarithmic plot of root-mean-square radius versus molecular weight of polymer.
• a typical linear random-coil polymer in a good solvent has a value between 0.5 and 0.6 (ref: P. J. Wyatt “ Review: Light scattering and the absolute characterization of macromolecules.” Analytica Chimica Acta. 272 (1993).
• a three-dimensional structured polymer is obtained when the apparent conformation coefficient deviates from that measured for a linear polymer.
• the value of a branched polymer is lower than 0.5 because of compact structure.
• the apparent conformation coefficient of polymers as described in “examples” was determined from top 20% of molecular weight distribution. All of the samples for SEC/MALLS analysis were pre-filtered with a syringe filter (Acrodisc® from PALL, pore size: 1.2 ⁇ m, diameter: 25 mm) to protect columns. The solubility of polymer is determined from polymer recovery that is the percentage of polymer eluted from SEC columns.
• the structured polymers are prepared by an aqueous polymerization reaction employing a redox reaction between the amine of the amine-containing monomer and an oxidizing initiator.
• a polymerization process for the acrylamide polymer in the present invention radical polymerization is preferred.
• a polymerization solvent a polar solvent such as water, an alcohol or dimethylformamide is preferred.
• Aqueous solution polymerization is however preferred when the acrylamide polymer is used as a paper strength agent.
• an organic solvent such as an alcohol can be used in combination to such an extent that the dispersibility would not be impaired by deposition or precipitation of the polymer
• the polymerization of the acrylamide polymer in the present invention can be conducted by such a batch process that all the monomers are charged at once in a reaction vessel and are then polymerized.
• an aqueous solution having a high concentration of 22% or more it is however more desired to conduct the polymerization by such a semi-batch process that the polymerization is conducted while adding dropwise a portion of or the entire portion of the monomers.
• This semi-batch polymerization process makes it possible not only to facilitate removal of polymerization heat from a solution containing monomers at high concentrations but also to control the molecular structure, for example, to facilitate the formation of the polymer into a uniform branched and compact structure.
• polymerization initiator No particular limitation is imposed on the polymerization initiator as long as it is an oxidant.
• a water-soluble polymerization initiator is preferred.
• the polymerization initiator can be added either at once or dropwise to the aqueous solution of the monomers.
• Specific examples of the polymerization initiator include, as persulfate and peroxide types, ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, benzoyl peroxide and tert-butyl peroxide.
• the polymerization process comprises initiating an aqueous solution of minimum of about 1 mole % amine monomer and any other co-monomers with a minimum of about 1 mole % (based on total moles of monomer(s)) of oxidant, such as persulfate.
• oxidant such as persulfate.
• the reaction temperature below about 60 C with a pH of about 4 or above provides optimal results.
• crosslinking is controlled by adding a suitable chain transfer agent (during or after polymerization), or by reducing the pH below about 3 after most of the monomers have polymerized.
• a polymer useful as a dry strength agent is prepared with the general process described above, except acrylamide is the predominant co-monomer.
• the weight average MW of the polymer must be >100,000 g/mol.
• Enhanced dry strength effects were obtained from polymers prepared from semi-batch addition of the anine monomer during polymerization. The other factors enhancing performance of the resulting polymer may include the use of monomer, which may dictate the need for semi-batch addition versus batch addition over the course of polymerization.
• the polymers and aqueous solutions so obtained can exhibit various excellent effects as paper strength agents.
• Use of the acrylamide polymers according to the present invention as paper strength agents is described in further detail.
• Dry strength was evaluated using standard procedures for handsheet making and testing.
• Treatment of the stock prior to sheet making included the addition of dry strength agent for two minutes followed by addition of a cationic retention aid.
• Handsheet making was conducted with a Noble & Woods handsheet former utilizing a single nip felted press and drum dried to bone dry conditions. Sheet strength was evaluated as tensile index, STFI index, and burst ratio using TAPPI standard methods. Sheet (basis) weights and apparent sheet densities (calculated from caliper and basis weight) were evaluated as check on the sheet making procedure and to ensure that strength comparisons were made at equal apparent sheet densities.
• Synthesis was carried out in a standard 1500 mL laboratory reactor equipped with a stainless steel stirring assembly (a half-moon Teflon blade and a non pitched impeller). The reactor was also equipped with heating and cooling capability. 243 g AcAm solution (49.5%) was added to a 1000 mL flask followed by 0.20 g EDTA, 16.36 g DMAEM, 647.84 g distilled water. 4.70 g sulfuric acid was added to adjust the pH to ⁇ 7.0. This solution was transferred to the reactor and cooled to 15° C. 7.50 g Sodium persulfate was dissolved in a beaker with 38 g of water and kept on the side.
• Synthesis was carried out in a standard 1500 mL laboratory reactor equipped with a stainless steel stirring assembly (a half-moon Teflon blade and a non pitched impeller). The reactor was also equipped with heating and cooling capability. 243 g AcAm solution (49.5%) was added to a 1000 mL flask followed by 0.20 g EDTA, 30.36 g DMAEM, 644.84 g distilled water. 6.70 g sulfuric acid was added to adjust the pH to ⁇ 7.0. This solution was transferred to the reactor and cooled to 15° C. 7.50 g Sodium persulfate (SPS) was dissolved in a beaker with 38 g of water and kept on the side.
• SPS Sodium persulfate
• Sodium hypophosphite was dissolved in 12 g of water and placed in a syringe attached to a syringe pump. 1.40 g sulfuric acid was dissolved in 11 g distilled water and kept in a beaker. The reaction was initiated with the addition of SPS solution at once and at the same time started 2 ml/min addition Sodium hypophosphite from the syringe pumps. At the end of reaction (about 6 minutes) the acid solution was added to kill the reaction and stabilize the product.
• Either process can be used in polymerization of co-monomers such as DMAPMA, DMAPAA, DMAEA with AcAm under similar batch or semi batch process.
• a 250 mL resin flask equipped with a mechanical stirrer and a nitrogen inlet was charged with 78 grams deionized water containing 128 ppm EDTA.
• a monomer solution comprised of 30 parts of 50 wt. % aqueous acrylamide and 4 parts DMAPMA were combined, and the resulting solution was purged with nitrogen for 30 minutes and then charged to a syringe.
• an initiator solution was prepared, by combining 4 parts water, 0.75 parts 50 wt. % sodium hydroxide, and 1.12 parts sodium persulfate, and placed in a syringe.
• a post-treat solution comprised of 0.5 parts sodium hypophosphite monohydrate dissolved in 2 parts water was also prepared.
• the water in the reactor was stirred and purged with nitrogen for 20 minutes. Then a continuous feed of the monomer solution to the reactor was started, followed by the commencement of a continuous feed of the initiator solution.
• the monomer solution was fed at a rate of about 7 mL/hr, and the initiator solution was fed at a rate of about 0.5 mL/hr.
• the reaction viscosity was carefully monitored until it reached a point, after about 58 minutes, where mixing was difficult and the reactor contents began to pull away from the reactor walls. At this point, the pre-prepared post-treat solution was added immediately to the reaction. The viscosity decreased and the reactor contents were cooled and dispensed, providing a structured AcAm/DMAPMA (90/10) copolymer solution.
• the monomer solution was comprised of 10 g DMAPAA dissolved in 31.7 g water and adjusted to pH 9 with 4.83 g concentrated HCl.
• the initiator solution was comprised of 0.2 sodium persulfate dissolved in a mixture of 0.13 g 50% NaOH and 7 g water. Both solutions were added over 2 hours to the stirring, nitrogen-purged resin flask contents. The reactor contents were allowed to mix further for 1 hour and then treated with 1.5 g concentrated HCl and 0.05 g sodium persulfate.
• the product comprised of an 11.3 wt. % solution of structured poly(DMAPAA) homopolymer.
• a poly(amidoamine) backbone 6.9 g of a 50% aqueous solution, and distilled (DI) water, 58.6 g.
• the poly(amidoamine) was made from adipic acid and diethylenetriamine.
• the solution was stirred at 200 rpm and purged with nitrogen for 30 minutes to remove all oxygen.
• Sodium persulfate 9.66 g of a 20% aqueous solution, was added to the solution at 25° C.
• the reaction temperature increased to 55° C. in 5 minutes as the polymerization progressed, and the solution became viscous.
• a warm water bath was used to hold the temperature at about 50° C. for 5 hr.
• the polymerization of acrylamide reached 99.8% conversion.
• the polymer was made from a 72:23:5 mole ratio mixture of monoallylamine, diallylamine, and triallylamine using a thermally activated azo initiator at high temperature in water.
• the DMAPMA monomer (3.16 g), acrylamide monomer (24.34 g of a 50 wt. % solution), and water (56 g) were combined in a beaker and adjusted to pH 4 with concentrated HCl (about 1.95 g, representing a small molar excess over the amount of DMAPMA used).
• the reaction solution was charged to a 250 mL resin flask equipped with a mechanical stirrer and a nitrogen inlet, and then purged with nitrogen for 20 minutes. Sodium persulfate, 0.3 g, was added and the reaction was allowed to stir overnight.
• the reaction was then diluted with 10 g water and post-treated with a solution of 0.5 g sodium hypophosphite monohydrate dissolved in 1.5 g water. This provided a linear AcAm/DMAPMA solution polymer for comparative purposes.
• Copolymers were synthesized under conditions for providing linear or structured AcAm copolymers. Evaluation of the apparent conformation coefficients in Table 1 indicates that the linear polymers (1* through 3*) have apparent coefficient values of greater than or equal to about 0.50 in contrast to non-linear structured copolymers (4* through 6** and 8** through 10**) with reduced values of about 0.25 to 0.30, which are consistent with polymer structuring. All structured polymers in Table 1 exhibited SEC column recovery greater than or equal to 80% solubility characteristic of water-soluble structured polymers described herein. TABLE 1 Measured Properties of Linear vs.
• Dry strength was evaluated using standard procedures for handsheet making and testing. The paper stock used and its treatment prior to sheet making are described as follows:
• Dosing Volumes 2700 mls @ 1.0 wt % total volume to split into 5 500 mls/Sheet Dosing Sequence 750 rpms with 2 turbine props, time, sec Event 2 in dia 0 Start 10 Add strength Additive 130 Add cationic 2 min 10 sec retention aid 150 Stop and make Sheets 2 min 30 sec
• the structured polymers of this invention are superior to linear polymer (3*, Table 1) as well as commercial dry strength additives used in manufacturing of paper products. Use of these polymers allows for equivalent dry strength at lower polymer dose compared to currently available dry strength agents.
• Each aqueous solution of an acrylamide structured polymer according to the present invention is, as shown in Table 2 have superior paper strength. These polymers are therefore economically excellent. When this polymer is used as a paper strength agent, it can exhibit comparable or better performance compared with conventional paper strength agents and is evidently excellent

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Paper (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Graft Or Block Polymers (AREA)

Priority Applications (13)

Applications Claiming Priority (1)

Related Child Applications (1)

Publications (1)

Family

ID=37308476

Family Applications (2)

Family Applications After (1)

Country Status (12)

Cited By (6)

Families Citing this family (6)

Citations (12)

Family Cites Families (3)

• 2005
  • 2005-05-03 US US11/120,878 patent/US20060249269A1/en not_active Abandoned
• 2006
  • 2006-04-26 BR BRPI0612341-4A patent/BRPI0612341B1/pt active IP Right Grant
  • 2006-04-26 AU AU2006242631A patent/AU2006242631B2/en not_active Ceased
  • 2006-04-26 ES ES06751405.9T patent/ES2476022T3/es active Active
  • 2006-04-26 PL PL06751405T patent/PL1877622T3/pl unknown
  • 2006-04-26 EP EP06751405.9A patent/EP1877622B1/en active Active
  • 2006-04-26 MX MX2007013772A patent/MX2007013772A/es active IP Right Grant
  • 2006-04-26 CA CA2608126A patent/CA2608126C/en active Active
  • 2006-04-26 CN CN200680015138.2A patent/CN101379098B/zh active Active
  • 2006-04-26 WO PCT/US2006/015676 patent/WO2006118875A2/en active Application Filing
  • 2006-05-03 MY MYPI20062039A patent/MY149268A/en unknown
• 2007
  • 2007-12-03 NO NO20076230A patent/NO341518B1/no unknown
• 2009
  • 2009-08-21 US US12/545,539 patent/US8530597B2/en active Active

Patent Citations (13)

Also Published As

Similar Documents

Legal Events