Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y40/00—Manufacture or treatment of nanostructures
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  • C08F212/00—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 an aromatic carbocyclic ring
  • C08F212/02—Monomers containing only one unsaturated aliphatic radical
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  • 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
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1804—C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
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  • 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
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1807—C7-(meth)acrylate, e.g. heptyl (meth)acrylate or benzyl (meth)acrylate
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  • 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
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1808—C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
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  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
  • C08F265/04—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00 on to polymers of esters
  • C08F265/06—Polymerisation of acrylate or methacrylate esters on to polymers thereof
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  • C08F287/00—Macromolecular compounds obtained by polymerising monomers on to block polymers
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  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F293/00—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule
  • C08F293/005—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent
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  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/18—Manufacture of films or sheets
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  • 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
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/65—Additives macromolecular
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
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  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/70—Additives characterised by shape, e.g. fibres, flakes or microspheres
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/38—Formation of filaments, threads, or the like during polymerisation
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F8/00—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof
  • D01F8/04—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers
  • D01F8/10—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers with at least one other macromolecular compound obtained by reactions only involving carbon-to-carbon unsaturated bonds as constituent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
• • 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
  • C08F2438/00—Living radical polymerisation
  • C08F2438/03—Use of a di- or tri-thiocarbonylthio compound, e.g. di- or tri-thioester, di- or tri-thiocarbamate, or a xanthate as chain transfer agent, e.g . Reversible Addition Fragmentation chain Transfer [RAFT] or Macromolecular Design via Interchange of Xanthates [MADIX]
• • C—CHEMISTRY; METALLURGY
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  • C08J2353/00—Characterised by the use of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/005—Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/28—Formation of filaments, threads, or the like while mixing different spinning solutions or melts during the spinning operation; Spinnerette packs therefor
  • D01D5/30—Conjugate filaments; Spinnerette packs therefor
  • D01D5/34—Core-skin structure; Spinnerette packs therefor
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2321/00—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D10B2321/08—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds polymers of unsaturated carboxylic acids or unsaturated organic esters, e.g. polyacrylic esters, polyvinyl acetate
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2321/00—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D10B2321/12—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds polymers of cyclic compounds with one carbon-to-carbon double bond in the side chain
  • D10B2321/121—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds polymers of cyclic compounds with one carbon-to-carbon double bond in the side chain polystyrene

Definitions

• RAFT reversible addition-fragmentation chain transfer
• RDRP reversible deactivation radical polymerization
• RAFT addition-fragmentation chain transfer
• AFCT addition-fragmentation chain transfer
• RAFT PISA can be implemented both as a dispersion polymerization and aqueous emulsion polymerization.
• RAFT-mediated PISA a solvophilic macroRAFT agent is chain extended with solvophobic core-forming monomer(s).
• the increasing insolubility of the core-forming block drives in-situ self-assembly resulting in block copolymer nanoparticles.
• the morphology is determined by a number of factors, but can largely be rationalized based on the relative molecular weights of the solvophilic block (i.e., the “corona” or shell-forming block) and the solvophobic block (core-forming block).
• the morphologies typically change from spheres, fibers and vesicles with increasing length of the solvophobic block.
• fillers additives
• traditional employed fillers e.g., carbon black and glass fibers
• traditional fillers tend to only offer limited material improvements in terms of a high fracture strain and stretchability.
• current fillers are typically difficult to disperse in a polymer matrix and surface modification is typically required, adding cost to the process.
• amphiphilic block copolymers are disclosed wherein the core is a copolymer that has a T g of about 75°C (and lower).
• amphiphilic block copolymers are disclosed wherein the core is a homopolymer and has a T g of about 16°C (and lower).
• nanofibers are disclosed wherein the core is a copolymer or a homopolymer having a T g up to 16°C.
• block copolymers are disclosed wherein the core and the shell are prepared from a hydrophobic copolymer or homopolymer.
• the present invention provides one or more of the following advantages: composites including the nanofiber of the invention that are tougher and/or have higher impact resistance; lower density composite materials comprising the nanofiber of the invention; nanofiber reinforced composites which have higher stiffness and are relatively lighter (of the order of about 10-20% weight reduction, which is a significant reduction; in some embodiments, the weight reduction is 5-40%); nanofiber reinforced composites which display higher elongation at break; nanofiber reinforced composites that are substantially transparent through matching refractive indices of the inventive nanofibers disclosed herein with the polymer matrix into which they are dispersed; and/or an improved control of rheological properties (thixotropy) of emulsions by use of the nanofibers of the invention.
• the nanofibers of the invention do not require surface modifications as the external surface, or shell, is solvophilic and can be wetted by polar polymers, solvents or other matrix, and they can relatively easily disperse in a polymer matrix. Furthermore, it is possible to prepare surface coatings and films that are substantially or completely formed from the nanofibers of the invention.
• the present invention provides a polymeric nanofiber having a core-shell morphology, wherein the shell is hydrophilic, and the core comprises: a) a hydrophobic copolymer, or b) a hydrophobic homopolymer having a T g below 16°C.
• the present invention provides an amphiphilic block copolymer comprising: a block [A] comprising a hydrophilic homo- or copolymer; and a block [B] comprising: a) a hydrophobic copolymer having a T g below about 75°C, or b) a hydrophobic homopolymer having a T g below about 16°C; and optionally a crosslinker.
• the hydrophobic homopolymer has a T g in the range of about -70°C and up to 16°C or about 16°C.
• the hydrophobic copolymer has a T g in the range of about -70°C to about 75°C.
• the present invention provides a method of producing the amphiphilic block copolymer of the second aspect, the method comprising the steps of: a) reacting at least one hydrophilic monomer using RDRP to form a hydrophilic block [A]; b) adding to hydrophilic block [A], a hydrophobic block [B] comprising at least one hydrophobic monomer using RDRP; and c) optionally adding a crosslinker at step b).
• the present invention provides a nanofiber when self- assembled from the amphiphilic block copolymer produced by the method of the third aspect.
• the present invention provides the use of the nanofiber of the first or fourth aspects to at least partially produce a film or coating.
• the present invention provides a method of forming the film or coating of the fifth aspect, the method comprising the steps of: dispersing the nanofiber of the first or fourth aspects in a solvent to form a dispersion; applying the dispersion to a surface; and allowing or causing the solvent to substantially or completely evaporate, thereby forming said film.
• the present invention provides the use of the nanofiber of the first or fourth aspects to prepare a composite material, comprising: a matrix or binder; and a nanofiber of the first or fourth aspects dispersed throughout the matrix or binder.
• the present invention provides the use of the nanofiber of the first or fourth aspects to modify or improve the mechanical properties of a matrix or binder.
• the present invention provides a method of producing a composite material, the method comprising the steps of: providing a polymer dispersion; dispersing the nanofiber of the first or fourth aspects in said polymer dispersion to form a mixture; and drying the mixture so as to form the composite material.
• the present invention provides a method of producing a composite material comprising a polymer and the nanofiber of the first or fourth aspects by melt extrusion, the method comprising the steps of: heating a polymer and the nanofiber to a temperature greater than a melt temperature of the polymer; mixing the polymer and the nanofiber; and extruding the mixture to form the composite material.
• the present invention provides the use of a polymeric nanofiber as a viscosity or rheology modifier, wherein the polymeric nanofiber comprises a core-shell morphology, wherein the shell is hydrophilic, and the core comprises a hydrophobic homopolymer or copolymer.
• the present invention provides the use of a polymeric nanofiber according to the first or fourth aspects as a viscosity or rheology modifier.
• the present invention provides the method of producing a block copolymer, the method comprising the steps of: a) reacting at least one hydrophobic monomer using RDRP to form a substantially hydrophobic block [A], wherein block [A] is substantially soluble in an 20/80 vol% water/ethanol mixture; b) adding to hydrophobic block [A], a hydrophobic block [B] comprising at least one hydrophobic monomer using RDRP in the presence of at least one polar solvent, wherein block [B] is more hydrophobic than block [A] and is a different composition to block [A]; and c) optionally adding a crosslinker at step b).
• the block copolymer produced according to the thirteenth aspect may self-assemble into a nanofiber having a core-shell morphology.
• block [A] is substantially insoluble in water.
• the nanofibers of the present invention are formed from polymers.
• the monomeric units may be of a single type (homopolymer), or a variety of types (copolymer).
• the physical behaviour of the polymer is dictated by several features, including the total molecular weight, the composition of the polymer (e.g., the relative concentrations of different monomers), the chemical identity of each monomeric unit and its interaction with a solvent, and the architecture of the polymer (e.g., whether it is single chain or branched chains).
• the present invention provides a process for preparing amphiphilic block copolymers comprising blocks [A] and [B], wherein block [A] is a hydrophilic homo- or copolymer, and wherein block [B] is a hydrophobic homopolymer having a T g below 16°C or about 16°C, or a hydrophobic copolymer having a T g of the hydrophobic block below about 75°C, wherein the process comprises obtaining blocks [A] and [B] by RDRP, preferably via RAFT of ethylenically unsaturated monomers and optionally comprising a crosslinker.
• the present invention provides a process for preparing block copolymers comprising blocks [A] and [B], wherein block [A] is a hydrophobic homo- or copolymer, and wherein block [B] is a hydrophobic homo- or copolymer, wherein the process comprises obtaining blocks [A] and [B] by RDRP, preferably via RAFT of ethylenically unsaturated monomers, and optionally comprising a crosslinker.
• RDRP preferably via RAFT of ethylenically unsaturated monomers, and optionally comprising a crosslinker.
• the present invention provides a block copolymer comprising: a hydrophobic block [A], wherein block [A] is substantially soluble in an 20/80 vol.% water / ethanol mixture; and a hydrophobic block [B] comprising at least one hydrophobic monomer, wherein block [B] is more hydrophobic than block [A] and is a different composition to block [A]; and optionally a crosslinker.
• the present invention provides a polymeric nanofiber having a core-shell morphology, wherein the shell is hydrophobic, and the shell comprises a polymer that is substantially soluble in an 20/80 vol.% water / ethanol mixture; and wherein the core is hydrophobic, and the core comprises a polymer that is more hydrophobic than the polymer of the shell, and is a different composition to the polymer of the shell.
• Use of the block copolymer of the fourteenth aspect or the polymeric nanofiber of the fifteenth aspect to at least partially produce a film or coating.
• block copolymer of the fourteenth aspect or the polymeric nanofiber of the fifteenth aspect to prepare a composite material, comprising: a matrix or binder; and a block copolymer of the fourteenth aspect or the polymeric nanofiber of the fifteenth aspect dispersed throughout the matrix or binder.
• Use of the block copolymer of the fourteenth aspect or the polymeric nanofiber of the fifteenth aspect to modify or improve the mechanical properties of a matrix or binder [0036] Use of the block copolymer of the fourteenth aspect or the polymeric nanofiber of the fifteenth aspect as a viscosity or rheology modifier.
• RAFT polymerization is one of the most robust and versatile methods for providing living characteristics to radical polymerization. With appropriate selection of the chain transfer agent (RAFT agent) for the monomers and reaction conditions, it is applicable to the majority of monomers subject to radical polymerization. The process can be used in the synthesis of well- defined homo-, gradient, diblock, triblock, and star polymers and more complex architectures, which include microgels and polymer brushes. [0038] When preparing, for example, a block copolymer in the presence of the chain transfer agent (RAFT agent), the end of the growing block is provided with a specific functionality that controls the growth of the block by means of RDRP.
• RAFT agent chain transfer agent
• the functionality at the end of the block is of such a nature that it can reactivate the growth of the block in a second and/or third stage of the polymerization process with other ethylenically unsaturated monomers providing a covalent bond between, for example, a first and second block [A] and [B] and with any further optional blocks.
• RAFT processes Further details on the chemistry of synthesis of block copolymers by RAFT processes can be found in the following publications, each of which is herein incorporated in its entirety by reference: Polymer, 2008, volume 49, 1079-1131; Chemical Society Reviews, 2014, volume 43, 496-505; Macromolecules, 1998, volume 31, 5559-5562; and Polymer, 2013, volume 54, 2011-2019.
• the block copolymer according to the disclosed and/or claimed inventive concepts is obtained by RAFT polymerization.
• Radical Initiators [0041] The radical initiator is chosen to have an appropriate half-life at the temperature of polymerization sufficient to initiate polymerization.
• Non-limiting examples of radical initiators suitable for the invention include one or more of the following compounds: 2,2'-azobis(isobutyronitrile ), 2,2'-azobis(2-cyanobutane), dimethyl 2,2'-azobis(isobutyrate), 4,4'-azobis(4-cyanovaleric acid), 4,4’-azobis-(4- cyanopentanoic acid), 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride, 1, 1 '- azobis(cyclohexanecarbonitrile), 2-(t-butylazo)-2-cyanopropane, 2,2'-azobis ⁇ 2-methyl-N-[1,1- bis(hydroxymethyl)-2-hydroxyethyl]propionamide ⁇ , 2,2'-azobis[2-methyl-N-(2- hydroxyethyl)propionamide], 2,2'-azobis(N,N'-dimethyleneisobutyramidine) dihydroch
• the radical initiator is 4,4’-azobis-(4-cyanopentanoic acid).
• the chain transfer agent is generally selected having regard to the type of monomers that are to be polymerized. Suitable chain transfer agents for use with the present invention include chain transfer agents for RDRP including, nitroxide-mediated radical polymerization (NMP), atom-transfer radical polymerization (ATRP), and RAFT. Other chain transfer agents will be known to the skilled person.
• R is selected from the group consisting of secondary cyanoalkyls such as cyanomethyl, 1-cyanoethyl, 2-cyanopropan-2-yl, primary and secondary alkoxylcarbonylalkyls such as ethoxycarbonylmethyl, 1- ethoxycarbonylethyl and primary and secondary carboxyalkyls, tertiary cyanoalkyls such as 2-cyanobutan-2-yl, 1- cyanocyclohexyl, 2-cyano-4-methylpentan-2-yl, 2-cyano-4- methoxy-4-methylpentan-2-yl, 2- cyano-4-carboxybutan-2-yl, 2-cyano-5-hydroxypentan-2-yl, secondary cyano(aryl)alkyls such as cyano(phenyl)methyl, tertiary alkoxylcarbonylalkyls such as 2-alkoxycarbonylpropan-2-yl, 1-
• the chain transfer agent has a structure of (II), (III), or (IV) wherein R, Z 1 , Z 2 , and Z 3 are as defined in Formula (I).
• the chain transfer agent is a RAFT agent.
• the chain transfer agents can be one or more compounds selected from the group consisting of dithiobenzoates, dithioesters, thioethers- thiones, trithiocarbonates, dithiocarbamates, xanthates and mixtures thereof.
• the RAFT agent is a macroRAFT agent.
• the term “macroRAFT” or “macroRAFT agent” means a RAFT agent which comprises one or more monomers.
• the macroRAFT agent is prepared by a method comprising polymerizing one or more unsaturated monomers under the control of a RAFT agent to form a macroRAFT agent.
• the macroRAFT agent is of the general formula (block [A])- RAFT, wherein block [A] is a hydrophilic polymer or copolymer as defined herein, and RAFT is a RAFT agent as described herein.
• the macroRAFT agent consists of a RAFT agent bound to a hydrophilic block of the present invention.
• the macroRAFT agent is P(AA-stat-PEGA)-DDMAT.
• the macroRAFT agent is P(AA-stat-PEGA)-TTC.
• Monomers [0056] Suitable polymers for the present invention include those that are prepared by any polymerization process. If desired, the monomers should also be capable of being polymerized with other monomers (e.g., a copolymer). The factors which determine copolymerizability of various monomers are well documented in the art.
• Suitable monomers that may be used in accordance with the invention include those of formula (V): where U and W are independently selected from -CO 2 H, -CO 2 R 1 , -COR 1 , -CSR 1 , - CSOR 1 , -COSR 1 , -CONH 2 , -CONHR 1 , -CONR 1 2 , hydrogen, halogen and optionally substituted C 1 -C 4 alkyl or U and W form together a lactone, anhydride or imide ring that may itself be optionally substituted, where the optional substituents are independently selected from hydroxy, -CO 2 H, -CO 2 R 1 , -COR 1 , -CSR 1 , -CSOR 1
• R 1 examples include those selected from alkyleneoxidyl (epoxy), hydroxy, alkoxy, acyl, alkylcarbonyl, carboxy, sulfonic acid, isocyanato, cyano, silyl, halo, amino, including salts and derivatives thereof.
• polymer chains include those selected from polyalkylene oxide, polyarylene ether and polyalkylene ether.
• Non-limiting examples of monomers include maleic anhydride, N-alkylmaleimide, Narylmaleimide, dialkyl fumarate and cyclopolymerizable monomers, acrylate and methacrylate esters, acrylic and methacrylic acid, styrene, acrylamide, methacrylamide, and methacrylonitrile, mixtures of these monomers, methyl methacrylate, ethyl methacrylate, propyl methacrylate (all isomers), butyl methacrylate (all isomers), 2- ethylhexyl methacrylate, isobornyl methacrylate, methacrylic acid, benzyl methacrylate, phenyl methacrylate, methacrylonitrile, alpha- methylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate (all isomers), butyl acrylate (all isomers e.g.,
• Non-limiting examples of acrylate monomers include methyl acrylate, methyl alpha- bromoacrylate, methyl 2-(bromomethyl)acrylate, methy12-(chloromethyl)acrylate, methyl 2-( trifluoromethyl)acrylate, ethyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 2-phenoxyethyl acrylate, alkoxylated phenol acrylates, alkoxylated tetrahydrofurfuryl acrylates, dicyclopentadienyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, ethoxylated hydroxyethyl acrylates, ethoxylated nonyl phenol acrylates, methoxy polyethylene glycol acrylates, polypropylene glycol acrylates, triethylene glycol ethyl ether acrylate, ethyl 2- (bromomethyl)acrylate, ethyl
• Block copolymers [0063]
• the present invention provides a process for preparing amphiphilic block copolymers comprising blocks [A] and [B], wherein block [A] is a hydrophilic homo- or copolymer, and wherein block [B] is a hydrophobic homopolymer having a T g below 16°C, or a hydrophobic copolymer having a T g of the hydrophobic block below about 75°C, wherein the process comprises obtaining blocks [A] and [B] by RDRP, preferably via a RAFT polymerization, of ethylenically unsaturated monomers.
• block [A] is a hydrophilic polymer or copolymer that has been formed by the polymerization of one or more monomers as described herein.
• block [A] is prepared from one or more of poly(ethylene glycol) methyl ether acrylate (PEGA), poly(ethylene glycol) methyl ether methacrylate (PEGMA), and acrylic acid.
• block [B] is a hydrophobic polymer or copolymer that has been formed by the polymerization of one or more monomers as described herein.
• block [B] is prepared from one or more of n- butyl acrylate (nBA), tert-butyl acrylate (tBA), and styrene.
• nBA n- butyl acrylate
• tBA tert-butyl acrylate
• the present invention provides a process for preparing block copolymers comprising blocks [A] and [B], wherein block [A] is a hydrophobic homo- or copolymer, and wherein block [B] is a hydrophobic homo- or copolymer, wherein the process comprises obtaining blocks [A] and [B] by RDRP, preferably via a RAFT polymerization, of ethylenically unsaturated monomers.
• block [A] is prepared from poly(methyl methacrylate) (PMMA).
• block [B] is prepared from one or more of benzyl methacrylate, ethyl hexyl methacrylate, and methyl methacrylate, preferably PMMA70-b-PBzMA40 or PMMA70-b-P(EHMA90-stat-MMA10).
• the glass transition temperature (T g ) for a polymer is defined as the temperature below which the long-range segmental motion of polymer chains and the coiling and uncoiling of segments of chains are both “frozen” and the polymer behaves like ‘solid glass’ or has crystalline properties. Below its T g , a polymer would not exhibit flow or rubber elasticity, however above its T g , a polymer exhibits flow or rubber elasticity. In other words, a polymer at a temperature below its T g is stiffer and less elastic than the same polymer at a temperature above its T g .
• block [B] comprises a hydrophobic copolymer selected to have a T g of the hydrophobic block below about 75°C, preferably in the range of -70°C to 75°C.
• block [B] comprises a hydrophobic homopolymer selected to have a T g below 16 °C, preferably in the range of -70°C to 16°C.
• Reaction conditions Conventional techniques, conditions and reagents used in preparing polymer by RAFT polymerization can advantageously be used in accordance with the invention.
• concentration of initiator(s), monomers, and other reaction conditions solvent(s) if any, reaction temperature, reaction pressure, surfactants if any, other additives
• concentration of initiator(s), monomers, and other reaction conditions should be chosen to optimise polymer properties, e.g. narrow dispersity polymers (good control/livingness as per a satisfactory RDRP (RAFT) process).
• Suitable ratios for the monomers of the block [A] include 1:100 to 100:1, or may be between about 1:100 and 1:1, or between about 1:1 and 1:100, or between about 50:1 and 1:50, or may be about 1:100, 1:95, 1:90, 1:85, 1:80, 1:75, 1:70, 1:65, 1:60, 1:55, 1:50, 1:45, 1:40, 1:35, 1:30, 1:25, 1:20, 1:15, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1 or 100:1 or any range therein.
• Suitable ratios for the monomers of the block [B] include 1:100 to 100:1 or may be between about 1:100 and 1:1, or between about 1:1 and 1:100, or between about 50:1 and 1:50, or may be about 1:100, 1:95, 1:90, 1:85, 1:80, 1:75, 1:70, 1:65, 1:60, 1:55, 1:50, 1:45, 1:40, 1:35, 1:30, 1:25, 1:20, 1:15, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1 or 100:1 or any range therein.
• the chain transfer agent may be present in any suitable concentration, for example between about 1 mmol.L -1 and about 1000 mmol.L -1 , or between about 10 mmol.L -1 and about 1000 mmol.L -1 , such as between about 5 mmol.L -1 and 20 mmol.L -1 , or between about 7 mmol.L- 1 and about 13 mmol.L -1 , or about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 mmol.L -1 or any range therein.
• the ratio of [hydrophobic monomer]:[chain transfer agent] is in the range of about 10 to about 400, or between about 100 to about 150, or between about 75 and about 100, or it may be about 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195 or 200 or any range therein. In one preferred embodiment, the ratio is in the range of about 40 to about 200.
• the polymerization temperature will be optimisable by the skilled person, taking into consideration the specific monomer(s) being polymerized and other components of the polymerization or reaction medium.
• Polymerization will generally be conducted at temperatures in the range of 20 to 100 °C, such as between about 0 and 180 °C, or between about 50 and 150 °C, or at about 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100°C or any range therein, preferably in the range of 40 to 100°C.
• Reaction times can range from 1 to 48 hours, for instance, from 1 to 20 hours, from 1 to 12 hours, or from 1 to 8 hours, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24 hours or any range therein.
• the polymerization may be conducted at any suitable pH range. In one embodiment, the pH is in the range of 3 to 8, or it may be between about 3.5 and about 6, or between about 4 and about 7, or at about 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or 8 or any range therein. [0083] In an embodiment, polymerization was carried out at 80°C in an oil bath with a stirring speed of 350 rpm for 6 hours.
• the reaction medium can be chosen from a wide range of media to suit the monomer(s) being used. For example, water and alcohols, such as methanol, ethanol, n-propanol, isopropylalcohol, n-butanol, n-pentanol, and mixtures thereof.
• the reaction medium can further include one or more of an acid, a base, a catalyst, a surfactant, and/or a coupling agent or any other suitable component.
• Hydrophobic and hydrophilic are not intended to define absolute qualities of a particular substance but rather to be an indicator of a favourable or unfavourable interactions (i.e., attractive or repulsive interactions).
• hydrophobic and hydrophobic are used herein as primary indicators to define characteristics such as like attracting like and unlike repelling unlike.
• a person skilled in the art might consider a “hydrophilic” liquid to have a solubility in water of at least 5 g/L at 25°C, and a “hydrophobic” liquid to have a solubility in water of less than 5 g/L at 25°C.
• a “hydrophilic” and “hydrophobic” might be considered by a person skilled in the art to be a reference to a solid which could be wetted by (i.e., does not repel) a hydrophilic and hydrophobic liquid, respectively.
• Molecular weights and dispersity index [0088] Those skilled in the art will appreciate that polymers exist as a distribution of chain lengths and molecular weights. Therefore, the molecular weight of a polymer must be described as an average molecular weight calculated from the molecular weights of all the chains in the sample.
• the molecular weight (MW) of block [A] or block [B] may be in the range of 5000 to 100,000, of it may be between about 10,000 and 100,000, or between about 25,000 and about 75,000, or it may be about 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 25000, 30000, 35000, 40000, 45000, 50000, 60000, 70000, 80000, 90000, 100000, 125000, 150000, 175000, 200000, 225000, 250000, 275000, 300000, 350000, 400000, 450000 or 500000 or any range therein.
• the molecular weight of block [A] or block [B] is in the range of 5000-40,000.
• the average degree of polymerization (DP) of a block copolymer as described herein is a value ranging from about 10 to about 1000, or between about 20 and about 500, or between about 50 and 750, or between and 300 and about 800, or about 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195 or 200 or any range therein.
• the degree of polymerization (DP) of the block copolymer is in the range of about 50 to about 300.
• Polymers prepared by the present invention can advantageously exhibit a well- defined molecular architecture, a predetermined molecular, weight and a narrow molecular weight distribution or low dispersity ( ⁇ ).
• Nanofiber dimensions [0092] As the skilled person would appreciate, the nanofibers of the present invention are defined as having a length that exceeds, or greatly exceeds, the width of the nanofibers.
• the ratio of length to width of the nanofibers may be greater than 5:1, or greater than 10:1, or greater than 25:1, or greater than 50:1, or greater than 100:1, or greater than 250:1, or greater than 500:1, or greater than 1000:1, or it may be between 5:1 and 200,000:1, or between 100:1 and 10,000:1, or between 500:1 and 5,000:1, or any range therein.
• the width of the nanofibers may be between about 1 nm and about 250 nm, or between about 3 nm and about 100 nm, or between 5 nm and about 50 nm, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160 ,165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245 or 250 nm or any range therein.
• each of the nanofibers may be between about 5 nm and 2 mm, or between about 10 nm and about 1 mm, or between about 50 nm and about 500 ⁇ m, or between about 20 nm and about 100 ⁇ m, or about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900 or 1000 nm, or 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900 or 1000 ⁇ m, or about 1.5 or 2 mm or any range therein.
• the amphiphilic block copolymer may be crosslinked to permanently stabilise the obtained nanofibers, and hence to give them long term stability.
• the crosslinker may provide a covalently-bound bridge between two different polymer chains. Any suitable crosslinking agent may be used. As the skilled person would appreciate, the crosslinker must have two terminal groups that are capable of radical polymerization and therefore incorporation into the polymer chain of the present invention. Examples of suitable crosslinking agents include, but are not limited to, an ethylene glycol diacrylate ester (e.g., ethylene glycol dimethylacrylate) when the monomeric material is an acrylate ester or an ethylene glycol diacrylic acid (e.g.
• the molar ratio of monomeric material to crosslinking agent in the solvent may be from 10:1 to 50:1, such as from 20:1 to 40:1.
• Non limiting examples of crosslinkers include (meth)acrylic anhydride, divinyl ethers of compounds selected from the group consisting of ethylene glycol, ethylene glycol diacrylate, poly(ethylene glycol) diacrylate, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11- unidecanediol, 1,12-dodecanediol, and combinations thereof; divinyl ethers of diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, nonaethylene glycol, decaethylene glycol, and polyal
• the crosslinker is selected from the group consisting of (meth)acrylic anhydride, methylenebis(meth)acrylamide, ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylamide, dipropylene glycol diallyl ether, polyglycol diallyl ether, hydroquinone diallyl ether, trimethylolpropane tri(meth)acrylate, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, and combinations thereof.
• the crosslinker may be added at any time-point of polymerization of the second block, including at the beginning, middle, or end.
• the crosslinker(s) can be present in an amount from about 0.001 % by weight to about 20 % by weight of the block copolymer. In another nonlimiting embodiment, the crosslinker(s) can be present in an amount from about 0.001 % by weight to about 10 % by weight of the block copolymer. In yet another non-limiting embodiment, the crosslinker(s) can be present in an amount from about 0.001 % by weight to about 5 % by weight of the block copolymer.
• the cross-linker may be present at about 0.001, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 % by weight or any range therein.
• the crosslinker is ethylene glycol diacrylate (EGDA) or ethylene glycol dimethacrylate (EGDMA).
• the crosslinker is poly(ethylene glycol) diacrylate (PEGDA).
• said nanofibers may further comprise an active agent encapsulated in the nanofibers.
• the term “encapsulated” refers to the enclosure of an active agent within the core of body of the nanofibers described herein.
• the active agent will be held within the polymer matrix of the nanofibers in the core of said nanofibers.
• nanofiber compositions that further comprise an active agent may contain from 0.01 to 50 weight% of the active agent relative to the weight of the nanofibers as a whole.
• the active agent may be present in an amount of from 1 to 30 weight%, such as from 5 to 10 weight% relative to the weight of the nanofibers as a whole.
• the active agent may be selected from one or more of the group consisting of vitamin C, peptides, glycerol, dyes, flavours, perfume oils, citronellal, silicon oils, organosilicons, pesticides, beta-carotene and a pharmacologically active agent.
• pharmaceutically active agent when used herein may refer to a substance useful for the treatment of or the prevention of a condition affecting a human or other animal. Said condition may be a disease, a disorder or a physiological condition.
• the active agent may not directly affect the underlying condition, but may be used as an adjuvant with a further active agent to enhance the effectiveness of the other active agent.
• the term “pharmacologically active agent” herein incudes all classes of pharmacologically active agents, whether adjuvant or therapeutic, that may be provided to a subject through oral administration.
• the term “pharmacologically active agent” and “drug” may be used interchangeably and so the term “drug” may be interpreted based on the definition of "active agent”.
• examples of pharmacologically active agents include, but are not limited to ibuprofen, fenofibrate, and isotrentinoin.
• Further active agents may include, but are not limited to, carbon metabolites (e.g. glucose, fructose, fumarate, etc.), electron acceptors (e.g. nitrate, peroxide, etc.), as well as a vitamin, such as vitamin A, B1, B2, B3, B6, B12, D, E, biotin, folate, and panothenate; minerals such as calcium, magnesium, selenium, and zinc; an amino acid such as asparagine, carnitine, glutamine, and serine; an antioxidant selected from coenzyme Q10, glutathione, and cysteine; or a metabolite such as lipoic acid, oleic add, choline, inositol, fructose, glucose, insulin, epigallocatechin gallate, and mixtures thereof.
• carbon metabolites e.g. glucose, fructose, fumarate, etc.
• electron acceptors e.g. nitrate, peroxide, etc.
• the nanofibers may have a core region that may comprise an active agent.
• the nature of the active agent in the core will be determined by the nature of the nanofibers that have been formed.
• nanofibers formed such that the hydrophilic blocks of the amphiphilic block copolymer are arranged on the surface of the nanofibers may be suitable for the encapsulation of hydrophobic active agents (as described hereinbefore).
• nanofibers are formed such that the hydrophobic blocks of the amphiphilic block copolymer are arranged on the surface of the nanofibers may be suitable for the encapsulation of hydrophilic active agents (as described hereinbefore).
• the nanofibers of the invention may have an average diameter of from 50 to 200 nm, such as from 70 to 150 nm.
• the hydrophobic repeating units will form the surface of the nanofibers, with the hydrophilic repeating units forming the core.
• the hydrophilic repeating units will form the surface of the nanofibers, with the hydrophobic repeating units forming the core.
• the hydrophobic repeating units will form the surface of the nanofibers, with hydrophobic repeating units also forming the core.
• nanofibers of the invention relate to: sun care compositions, face care compositions, lip care compositions, eye care compositions, skin care compositions, after- sun compositions body care compositions nail care compositions anti aging compositions insect repellants, oral care compositions, deodorant compositions, hair care compositions, conditioning compositions, color cosmetic compositions, color-protection compositions, self- tanning compositions, and foot care compositions.
• the nanofibers disclosed herein may also be used as a filler and/or a reinforcing agent for a composite material. In other words, said nanofibers may be encapsulated in, or dispersed through, a matrix material. The nanofibers may alter the physical properties of the formed composite material.
• the nanofibers may be added to, or dispersed throughout, the matrix during production of the composite material, such as when the matrix is dissolved in or dispersed throughout a solvent such as water, or is molten.
• the matrix may comprise a polymer as described herein so as to form a composite polymer material, such as a film, or a coating, or a formed article.
• the polymer matrix may preferably be hydrophilic, or formed from an aqueous dispersion, so that the hydrophilic shell of the nanofibers is wetted by the matrix during production.
• the nanofibers may be mixed with the aqueous dispersion before curing.
• the nanofibers may be added to an extruder with the polymer pellets and mixed during or after the melting of the polymer matrix material.
• the matrix may comprise a hydraulic binder, such as cement (e.g., Portland cement) or fly ash, in which the nanofibers may be added to hydraulic binder before addition of water, or after the addition of water, or sequentially with the water, and then mixed to produce a cementitious material comprising the nanofibers of the present invention.
• the matrix may comprise a mineral material, such as calcium sulfate (i.e., gypsum) in the production of plaster-based articles, such as plasterboard/drywall.
• the matrix may be any substance that would benefit from modification of the viscosity and/or rheology of the matrix.
• the nanofibers may be used as viscosity modifiers for a range of liquid or semi-solid materials, such as gels, hydraulic fluids and the like.
• the nanofibers of the present invention may be used to replace fillers and/or reinforcing agents in other known materials, in which the effect of the low T g core would result in a beneficial effect.
• FIG. 11 Schematic illustration of block copolymers with a first hydrophilic block and a second hydrophobic block self-assembled into nanofibers with a hydrophilic outside ‘shell’ portion and a hydrophobic inside ‘core’ portion used in the preparation of nanofiber-reinforced nanocomposite polymer materials.
• wt.% refers to the weight of a particular component relative to total weight of the referenced composition.
• nanofiber refers to a solid nanoparticulate material that is similar to a micelle in that it has a solid core and a solid shell/corona (i.e., the interior portion of the cylinder is not hollow).
• the core and shell are formed from the polymeric material, with the hydrophilic blocks on the exterior surface of the nanofiber (to form the shell) and the hydrophobic blocks forming the core of the nanofiber (or vice versa).
• the hydrophobic blocks are on the exterior surface of the nanofiber with hydrophobic blocks also forming the core of the nanofiber. While the shell is solid, these nanofiber may have the capacity to be used as a carrier because other molecules (e.g., active agents) can still be dispersed within the core of the cylindrical nanofiber (e.g. by diffusion or other suitable means), thereby allowing the cylindrical nanofiber to act as a carrier for an active agent.
• active agents e.g., active agents
• each independently selected from the group consisting of means when a group appears more than once in a structure, that group can be selected independently each time it appears.
• alkyl refers to a functionalized or unfunctionalized, monovalent, straight chain, branched-chain, or cyclic C 1 -C 60 hydrocarbyl group optionally having one or more heteroatoms.
• an alkyl is a C 1 -C 45 hydrocarbyl group.
• an alkyl is a C 1 -C 30 hydrocarbyl group.
• Non-limiting examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, tert-octyl, iso-norbomyl, n-dodecyl, tert-dodecyl, n- tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.
• alkyl also includes groups obtained by combinations of straight-chain, branched-chain and/or cyclic structures.
• aryl refers to a functionalized or unfunctionalized, monovalent, aromatic hydrocarbyl group optionally having one or more heteroatoms.
• the definition of aryl includes carbocyclic and heterocyclic aromatic groups.
• Non-limiting examples of aryl groups include phenyl, naphthyl, indenyl, indanyl, azulenyl, fluorenyl, anthracenyl, furyl, thienyl, pyridyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, 2-pyrazolinyl, pyrazolidinyl, isoxazolyl, isothiazolyl, 1,2,3-oxadiazolyl, 1,2,3-triazolyl, 1,3,4-thiadiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, 1,3,5-triazinyl, 1,3,5-trithianyl, indolizinyl, indolyl, isoindolyl, 3H-indolyl, indoliny1, benzo[b]furany1, 2,3-dihydrobenzofur
• alkylene refers to a functionalized or unfunctionalized, divalent, straight chain, branched-chain, or cyclic C 1 -C 40 hydrocarbyl group optionally having one or more heteroatoms.
• an alkylene is a C 1 -C 30 group.
• an alkylene is a C 1 -C 20 group.
• Non-limiting examples of alkylene groups include: [00147]
• the term "heteroatom” refers to oxygen, nitrogen, sulfur, silicon, phosphorous, or halogen. The heteroatom(s) can be present as a part of one or more heteroatom-containing functional groups.
• heteroatom-containing functional groups include ether, hydroxy, epoxy, carbonyl, carboxamide, carboxylic ester, carboxylic acid, imine, imide, amine, sulfonic, sulfonamide, phosphonic, and silane groups.
• the heteroatom(s) can also be present as a part of a ring such as in heteroaryl and heteroarylene groups.
• alkenyl denotes groups formed from straight chain, branched or cyclic hydrocarbon residues containing at least one carbon to carbon double bond including ethylenically mono-, di- or polyunsaturated alkyl or cycloalkyl groups as previously defined, preferably C 2-20 alkenyl (e.g. C 2-10 or C 2-6 ).
• alkenyl examples include vinyl, allyl, 1- methylvinyl, butenyl, iso-butenyl, 3-methyl-2-butenyl, 1-pentenyl, cyclopentenyl, 1-methyl- cyclopentenyl, 1-hexenyl, 3-hexenyl, cyclohexenyl, 1-heptenyl, 3-heptenyl, 1-octenyl, cyclooctenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-decenyl, 3-decenyl, 1,3-butadienyl, 1,4- pentadienyl, 1,3-cyclopentadienyl, 1,3-hexadienyl, 1,4-hexadienyl, 1,3-cyclohexadienyl, 1,4- cyclohexadienyl, 1,3-cycloheptadienyl, 1,3,5- cyclo
• alkenyl group may be optionally substituted by one or more optional substituents as herein defined.
• alkynyl denotes groups from straight chain, branched or cyclic hydrocarbon residues containing at least one carbon-carbon triple bond including ethylenically mono-, di- or polyunsaturated alkyl or cycloalkyl groups as previously defined. Unless the number of carbon atoms is specified the term preferably refers to C 2-20 alkynyl (e.g. C 2-10 or C 2-6 ), Examples include ethynyl, 1-propynyl, 2-propynyl, and butynyl isomers, and pentynyl isomers.
• alkynyl group may be optionally substituted by one or more optional substituents as herein defined.
• carbocyclyl refers to non-aromatic monocyclic, polycyclic, fused or conjugated hydrocarbon residues, preferably C 3-20 (e.g. C 3-10 or C 3-8 ).
• the rings may be saturated, e.g. cycloalkyl, or may possess one or more double bonds (cycloalkenyl) and/or one or more triple bonds (cycloalkynyl).
• Particularly preferred carbocyclyl moieties are 5-6 membered or 9- 10 membered ring systems.
• Suitable examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cyclopentenyl, cyclohexenyl, cyclooctenyl, cyclopentadienyl, cyclohexadienyl, cyclooctatetraenyl, indanyl, decalinyl and indenyl.
• a carbocyclyl group may be optionally substituted by one or more optional substituents as herein defined.
• the term "carbocyclylene" is intended to denote the divalent form of carbocyclyl.
• heterocyclyl refers to a stable 3- to 18-membered ring (radical) which consists of carbon atoms and from one to five heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur.
• Thes heterocycle may be a monocyclic, or a polycyclic ring system, which may include fused, bridged, or spiro ring systems; and the nitrogen, carbon, or sulfur atoms in the heterocycle may be optionally oxidized; the nitrogen atom may be optionally quaternized; and the ring may be partially or fully saturated.
• heterocycles include, without limitation, azepinyl, azocanyl, pyranyl, dioxanyl, dithianyl, 1,3-dioxolanyl, tetrahydrofuryl, dihydropyrrolidinyl, decahydroisoquinolyl, imidazolidinyl, isothiazolidinyl, isoxazolidinyl, morpholinyl, octahydroindolyl, octahydroisoindolyl, 2-oxopiperazinyl, 2- oxopiperidinyl, 2-oxopyrrolidinyl, 2-oxoazepinyl, oxazolidinyl, oxiranyl, piperidinyl, piperazinyl, 4-piperidonyl, pyrrolidinyl, pyrazolidinyl, thiazolidinyl, tetrahydropyranyl, thiamorpholin
• heteroaryl means an aromatic monocyclic or multi-cyclic ring system of about 5 to about 19 ring atoms, or about 5 to about 10 ring atoms, in which one or more of the atoms in the ring system is/are element(s) other than carbon, for example, nitrogen, oxygen, or sulfur.
• element(s) other than carbon for example, nitrogen, oxygen, or sulfur.
• heteroaryl In the case of multi-cyclic ring system, only one of the rings needs to be aromatic for the ring system to be defined as “heteroaryl”.
• Particular heteroaryls contain about 5 to 6 ring atoms.
• aza, oxa, thia, or thio before heteroaryl means that at least a nitrogen, oxygen, or sulfur atom, respectively, is present as a ring atom.
• a nitrogen, carbon, or sulfur atom in the heteroaryl ring may be optionally oxidized; the nitrogen may optionally be quaternized.
• Representative heteroaryls include pyridyl, 2-oxo-pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, furanyl, pyrrolyl, thiophenyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, indolyl, isoindolyl, benzofuranyl, benzothiophenyl, indolinyl, 2-oxoindolinyl, dihydrobenzofuranyl, dihydrobenzothiophenyl, indazolyl, benzimidazolyl, benzo
• Preferred acyl groups include wherein R e is hydrogen or an alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl residue. Examples of acyl include formyl, straight chain or branched alkanoyl (e.g.
• C 1-20 such as acetyl, propanoyl, butanoyl, 2-methylpropanoyl, pentanoyl, 2,2-dimethylpropanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, undecanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, pentadecanoyl, hexadecanoyl, heptadecanoyl, octadecanoyl, nonadecanoyl and icosanoyl; cycloalkylcarbonyl such as cyclopropylcarbonyl, cyclobutylcarbonyl, cyclopentylcarbonyl and cyclohexylcarbonyl; aroyl such as benzoyl, toluoyl and naphthoyl; aralkano
• phenylacetyl phenylpropanoyl, phenylbutanoyl, phenylisobutylyl, phenylpentanoyl and phenylhexanoyl
• naphthylalkanoyl e.g.
• aralkenoyl such as phenylalkenoyl (eg phenylpropenoyl phenylbutenoyl, phenylmethacryloyl, phenylpentenoyl and phenylhexenoyl and naphthylalkenoyl (e.g.
• aryloxyalkanoyl such as phenoxyacetyl and phenoxypropionyl
• arylthiocarbamoyl such as phenylthiocarbamoyl
• arylglyoxyloyl such as phenylglyoxyloyl and naphthylglyoxyloyl
• arylsulfonyl such as phenylsulfonyl and napthylsulfonyl
• heterocycliccarbonyl heterocyclicalkanoyl such as thienylacetyl, thienylpropanoyl, thienylbutanoyl, thienylpentanoyl, thienylhexanoyl, thiazolylacetyl, thiadiazolylacetyl and tetrazolylacetyl
• R e residue may be optionally substituted as described herein.
• sulfoxide refers to a group -S(O)R f wherein R f is selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, carbocyclyl, and aralkyl. Examples of preferred R include C 1-20 alkyl, phenyl and benzyl.
• sulfonyl refers to a group S(O) 2 -R f , wherein R f is selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, carbocyclyl and aralkyl. Examples of preferred R f include C 1-20 alkyl, phenyl, and benzyl.
• sulfonamide refers to a group S(O)NR f R f wherein each R f is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocyclyl, carbocyclyl, and aralkyl.
• R f examples include C 1-20 alkyl, phenyl and benzyl. In one embodiment at least one R f is hydrogen. In another embodiment, both R f are hydrogen.
• the term "amino" is used here in its broadest sense as understood in the art and includes groups of the formula NR a R b wherein R a and R b may be independently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, carbocyclyl, heteroaryl, heterocyclyl, arylalkyl, and acyl. R a and R b together with the nitrogen to which they are attached, may also form a monocyclic, or polycyclic ring system e.g.
• amino examples include NH 2 , NHalkyl (e.g. C 1-20 alkyl), NHaryl (e.g. NHphenyl), NHaralkyl (e.g. NHbenzyl), NHacyl (e.g. NHC(O)C 1-20 alkyl, NHC(O)phenyl), Nalkylalkyl (wherein each alkyl, for example C 1-20 , may be the same or different) and 5 or 6 membered rings, optionally containing one or more same or different heteroatoms (e.g. O, N and S).
• NHalkyl e.g. C 1-20 alkyl
• NHaryl e.g. NHphenyl
• NHaralkyl e.g. NHbenzyl
• NHacyl e.g. NHC(O)C 1-20 alkyl, NHC(O)phenyl
• Nalkylalkyl wherein each alkyl, for example C 1-20 , may
• amido is used here in its broadest sense as understood in the art and includes groups having the formula C(O)NR a R b , wherein R a and R b are as defined as above.
• amido include C(O)NH 2 , C(O)NHalkyl (e.g. C 1-20 alkyl), C(O)NHaryl (e.g. C(O)NHphenyl), C(O)NHaralkyl (e.g. C(O)NHbenzyl), C(O)NHacyl (e.g.
• [group A][alkyl] refers to a particular group A (such as hydroxy, amino, etc.) when linked by divalent alkyl, i.e. alkylene (e.g. hydroxyethyl is intended to denote HO-CH2-CH-).
• groups written as "[group]oxy” refer to a particular group when linked by oxygen, for example, the terms “alkoxy” or “alkyloxy”, “alkenoxy” or “alkenyloxy”, “alkynoxy” or alkynyloxy”, “aryloxy” and “acyloxy”, respectively, denote alkyl, alkenyl, alkynyl, aryl and acyl groups as hereinbefore defined when linked by oxygen.
• stable compound or “stable structure” mean a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious agent.
• functionalized with reference to any moiety refers to the presence of one or more functional groups in the moiety. Various functional groups can be introduced in a moiety by way of one or more functionalization reactions known to a person having ordinary skill in the art.
• Non-limiting examples of functionalization reactions include: alkylation, epoxidation, sulfonation, hydrolysis, amidation, esterification, hydroxylation, dihydroxylation, amination, ammonolysis, acylation, nitration, oxidation, dehydration, elimination, hydration, dehydrogenation, hydrogenation, acetalization, halogenation, dehydrohalogenation, Michael addition, aldol condensation, Canizzaro reaction, Mannich reaction, Clasien condensation, Suzuki coupling, and the like.
• the term "functionalized” with reference to any moiety refers to the presence of one more functional groups selected from the group consisting of alkyl, alkenyl, hydroxyl, carboxyl, halogen, alkoxy, amino, imino, and combinations thereof, in the moiety.
• the term “monomer” refers to a small molecule that chemically bonds during polymerization to one or more monomers of the same or different kind to form a polymer.
• polymer refers to a large molecule comprising one or more types of monomer residues (repeating units) connected by covalent chemical bonds.
• polymer encompasses compounds wherein the number of monomer units can range from very few, which more commonly can be called as oligomers, to very many.
• Non-limiting examples of polymers include homopolymers, copolymers, terpolymers, tetrapolymers and the higher analogues.
• the polymer can have a random, block, and/or alternating architecture.
• homopolymer refers to a polymer that consists of a single monomer type.
• copolymer refers to a polymer that comprises at least two different monomer types.
• terpolymer refers to a copolymer that comprises three different monomer types.
• branched refers to any non-linear polymer structure.
• the term includes both branched and hyper-branched structures.
• block copolymer refers to a polymer comprising at least two blocks of polymerized monomers. Any block can be derived from either a single monomer resulting in a homopolymeric subunit, or two or more monomers resulting in a copolymeric (or nonhomopolymeric) subunit in the block copolymer.
• the block copolymers can be di block copolymers (i.e., polymers comprising two blocks of monomers), triblock copolymers (i.e., polymers comprising three blocks of monomers), multiblock copolymers (i.e., polymers comprising more than three blocks of monomers), and combinations thereof.
• the block copolymers can be linear, branched, star or comb like, and have structures such as [A][B], [A][B][A], [A][B][C], [A][B][A][B], [A][B][C][B], etc.
• block copolymer is [A]x[B]y or [A]x[B]y[C]z, wherein x, y and z are the degrees of polymerization (DP) of the corresponding blocks [A], [B] and [C]. Additional insight into the chemistry, characterization and applications of block copolymers can be found in the book 'Block Copolymers: Synthetic Strategies, Physical Properties, and Applications', by Nikos Hadjichristidis, Stergios Pispas, and George Floudas, John Wiley and Sons (2003), the contents of which are herein incorporated in its entirety by reference.
• reversible deactivation radical polymerization (RDRP), "controlled radical polymerization” or “controlled/living radical polymerization” refer to a specific radical polymerization process, also denoted by the term of "living radical polymerization”, in which use is made of control agents, such that the polymer chains being formed are functionalized by end groups capable of being reactivated in the form of free radicals by virtue of reversible transfer or reversible termination reactions, thus enabling synthesis of e.g. block copolymers.
• additional-fragmentation refers to a two-step chain transfer mechanism during polymerization wherein a radical addition is followed by fragmentation to generate a new radical species.
• the term "residue of at least one crosslinker” refers to one or more cross-linking moieties that become a part of the polymer backbone after polymerization. The residue can be mono-, di- or polyvalent.
• the term " radical addition polymerization initiator” refers to a compound used in a catalytic amount to initiate a radical addition polymerization. The choice of initiator depends mainly upon its solubility and its decomposition temperature.
• alkyl acrylate refers to an alkyl ester of an acrylic acid or an alkyl acrylic acid.
• alkyl acrylamide refers to an alkyl amide of an acrylic acid or an alkyl acrylic acid.
• composition refers to any composition comprising at least one pharmaceutically active ingredient, as well as any product which results, directly or indirectly, from combination, complexation, or aggregation of any two or more of the ingredients, from dissociation of one or more of the ingredients, or from other types of reactions or interactions of one or more of the ingredients.
• coating composition refers to an aqueous-based or solvent-based liquid composition that can be applied to a substrate and thereafter solidified (for example, by radiation, air curing, post-crosslinking or ambient temperature drying) to form a hardened coating on the substrate.
• Inhibitors in styrene (‘S’, 99%, Sigma-Aldrich), n-butyl acylate (‘nBA’, 99%, Sigma-Aldrich), methyl methacrylate (‘MMA’, 99%, Sigma-Aldrich), benzyl methacrylate (‘BzMA’, 99%, Sigma-Aldrich) and 2-ethylhexyl methacrylate (‘EHMA’, 99%, Sigma-Aldrich) were removed by passing through an aluminum oxide column before use. Azobis(isobutyronitrile) (‘AIBN’, Sigma-Aldrich) in acetone was precipitated in water. Water was deionized before use (milli-Q water).
• AIBN Azobis(isobutyronitrile)
• the RAFT agent 2-(dodecylthiocarbonothioylthio)-2- methylpropionic acid (‘DDMAT’) and 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid (‘CPADB’) were synthesized according to the literature.
• Two-step synthesis of P(AA-stat-PEGA)-b-P(S-stat-nBA) amphiphilic block copolymers [00182] The experiments are labelled A-x, B-x, C-x, D-x, E-x, and F-x (x is the experiment number).
• Entries A-x is RAFT aqueous emulsion polymerization of styrene and nBA performed at different pHs.
• Entries B-x is RAFT aqueous emulsion polymerization of styrene and nBA performed at pH 5 with different molar ratios [hydrophobic monomer]:[macroRAFT] (Scheme 1).
• Entries C-x, D-x, E-x, and F-x refer to synthesis of crosslinked P(AA-stat-PEGA)-b-P(S-stat- nBA) nanofibers (Scheme 2).
• the solution was mixed in a 25 mL glass vial at ambient temperature for 10 min, and subsequently purged for 30 min with nitrogen in an ice bath. Polymerization was carried out at 70°C in an oil bath with a stirring speed of 500 rpm for 3 h. The final overall conversion of AA and PEGA was 95% as determined by 1 H NMR.
• the obtained final polymerization mixture was added dropwise into 35 mL of diethyl ether in a 50 mL centrifuge tube, and centrifuged at 7000 rpm for 5 min. The product was precipitated in diethyl ether after centrifugation, and the supernatant was discarded.
• ACPA, NaHCO3, P(AA-stat-PEGA)-DDMAT, and milli-Q water were added into a 25 mL glass vial.
• the solution was mixed using a sonication bath for 10 min. Different amounts of 1 M NaOH were added in Entries A-x to observe the effect of the pH.
• pH of the solution was not adjusted (0 ⁇ L of 1M NaOH).
• 1 M NaOH solution was added to adjust the pH (290 ⁇ L of 1 M NaOH was added for A-2, and 930 ⁇ L for A-3).
• M macroRAFT , M S , M nBA are the molar masses of macroRAFT agent, styrene, and nBA, respectively
• [macroRAFT] 0 , [styrene] 0 , [nBA] 0 are the initial concentrations of macroRAFT agent, styrene, and nBA, respectively
• Xconv. denotes total monomer conversion determined by gravimetry.
• the first approach was to introduce EGDA prior to the RAFT aqueous emulsion polymerization of styrene and nBA, whereas the second approach was to introduce EGDA after 2 h of polymerization (conversion > 90%).
• the ratio [hydrophobic monomer] 0 /[macroRAFT] 0 was fixed at 100. After polymerization, 120 ⁇ L of the latex was added to 1 mL of THF (volume ratio ⁇ 10/90) to observe whether the polymer particles dissolve in THF – insolubility indicates crosslinking has been achieved.
• the pH of the solution was adjusted to pH 5 by adding 290 ⁇ L of 1 M NaOH for Entries G-x (Table SI-1) and 290 ⁇ L, 580 ⁇ L, and 870 ⁇ L of 1M NaOH for H-1, H-2, and H-3 (Table SI-2).
• Styrene and nBA with different [hydrophobic monomer] 0 /[macroRAFT] 0 was added to the solution after adjusting the pH for Entries G-x.
• the conversion of styrene and nBA was determined by gravimetric analysis.
• Theoretical Mn,th was determined by eqn (SI- 1). All experiments are summarized in Table SI-1 (Entries G-x) and Table SI-2 (Entries H-x). Gravimetric Analysis. [00189] The total conversion of styrene and nBA was determined by gravimetric analysis. Latex at different time intervals were taken to observe progression of monomer conversion over time.950 ⁇ L of the latex was weighed in a pre-weighed aluminium pan and dried in a 50°C vacuum oven overnight. Nuclear Magnetic Resonance (NMR).
• NMR Nuclear Magnetic Resonance
• M n and M w weight-average molecular weights and dispersity ( ⁇ ) were determined by gel permeation chromatography (GPC) using a Shimadzu modular system, comprising an SIL-10AD autoinjector, an LC-10AT pump, a DGU-12A degasser, a CTO-10A column oven, and an RID-10A differential refractive index detector.
• GPC gel permeation chromatography
• a column arrangement consisting of a Polymer Laboratories 5.0 ⁇ m bead size guard column (50 ⁇ 7.8 mm), followed by four linear PL column (300 ⁇ 7.8 mm, 500, 10 3 , 10 4 , and 10 5 ⁇ , 5 ⁇ m pore size) was used for the analysis.
• N,N-Dimethylacetamide (DMAc, 0.03% w/v LiBr, 0.05% w/v 2,6-dibutyl-4- methylphenol(BHT)) was used as the mobile phase at 50°C and flow rate of 1 mL min -1 .
• the SEC system was calibrated using linear polystyrene standards ranging from 500 to 10 6 g mol -1 (Polymer Laboratories). Chromatograms were processed using Cirrus 2.0 software (Polymer Laboratories). Samples were methylated to modify the carboxylic group in acrylic acid to reduce the interaction with the column.
• the dried latex (10 mg) was added to 1 mL of milli-Q water in a 25 mL glass vial and HCl was added to adjust to pH 3-4. Then, 20 mL of THF was added to the mixture. Trimethylsilyldiazomethane methylating agent was added into the vial drop by drop. The mixture was stirred at room temperature for 4 h. After methylation, the solution was dried in an aluminium pan at ambient temperature overnight. It was further dried at 35°C using high vacuum oven for 1 h to remove water. Samples were dissolved in DMAc and filtrated using a syringe filter (0.45 ⁇ m) prior to injection into the GPC system. Transmission Electron Microscopy (TEM).
• TEM Transmission Electron Microscopy
• TEM samples were prepared by dropping 10 ⁇ L of diluted latex (10 ⁇ L of latex in 1 mL of milli-Q water) on a glow-discharged formvar-coated copper grid, which was dried at ambient temperature.
• the grid was glow-discharged to modify the grid surface from hydrophobic to hydrophilic to avoid accumulation of block copolymer nanoparticles on the periphery of the grid.
• the TEM images were obtained under an accelerating voltage of 100 kV using a JEOL 1400 transmission electron microscope.
• the spherical morphology obtained at pH 7 can presumably be rationalized by negative charges generated by deprotonation of AA hindering the reorganization of spheres into higher order morphology by electrostatic repulsion.
• EGDA and PEGDA When added at the beginning of the polymerization (Method (i)), EGDA and PEGDA (Entries C-x, and D-x) interfered with the PISA process, affecting the final morphology.
• thinner (Fig.6; C-2) and shorter (Fig.6; C-3) nanofibers were obtained with 1 or 2.5 mol% PEGDA.
• EGDA Entries D-x
• relatively pure nanofibers Fig.6; D-1, and D-2 were obtained with 0.5 or 1 mol% EGDA whereas spherical micelles were obtained when 10 mol% EGDA was introduced (Fig.6; D-3).
• Crosslinked nanofibers/vesicles may be obtained by introducing crosslinker at the beginning of polymerization (Method (i)) and delaying the introduction of crosslinker (Method (ii)) once the desired morphology has been formed.
• Method (i) the beginning of polymerization
• Method (ii) the introduction of crosslinker
• Method (ii) the introduction of crosslinker
• THF is a good solvent for the linear diblock copolymer, i.e. transparent solutions indicate minimal (if any) crosslinking, whereas turbid solutions are consistent with significant crosslinking.
• the pH was 5.
• preferred embodiments utilised crosslinking of the core-block using the divinyl monomers poly(ethylene glycol) diacrylate (PEGDA) and ethylene glycol diacrylate (EGDA) respectively that were introduced either at the beginning of the PISA process or towards the end of the growth of the core-forming block.
• PEGDA poly(ethylene glycol) diacrylate
• EGDA ethylene glycol diacrylate
• the nature of the crosslinker and the time of addition can influence the nanofiber morphology.
• addition of the crosslinker at the beginning or late in the polymerization maintained nanofiber morphology while crosslinking successfully.
• Supplemental information [00210] Table SI-1.
• M n,th The theoretical number-average molecular weight (M n,th ) was determined by eqn (SI- 1): Table SI-2.
• Example SI-1 block copolymers comprising hydrophobic monomers were prepared via dispersion polymerization. Previous works have shown PISA can be conducted in non-polar solvent such as dodecane and mineral oil using hydrophobic monomers. However, such non-polar solvents have usually high boiling point and are difficult to remove.
• non-polar solvent such as dodecane and mineral oil using hydrophobic monomers. However, such non-polar solvents have usually high boiling point and are difficult to remove.
• hydrophobic block copolymer in a mixture of water and alcohol.
• the hydrophobic monomer is substantially insoluble in water and/or substantially soluble in an 80/20 vol% ethanol/water mixture.
• the solution was mixed in a 25 mL glass vial at ambient temperature for 10 min, and subsequently purged for 30 min with nitrogen in an ice bath. Polymerization was carried out at 70 °C in an oil bath with a stirring speed of 500 rpm for 20 h.
• the final conversion of MMA was 78% as determined by 1 H NMR.
• the final polymerization mixture was added dropwise into 35 mL of diethyl ether in a 50 mL centrifuge tube, and centrifuged at 7000 rpm for 5 min. The precipitated product was collected after centrifugation, and the supernatant was discarded. The product was redissolved in toluene after precipitation, and subsequently added dropwise into 35 mL of fresh diethyl ether and mixed well before centrifugation. This process was repeated three times. The purified samples were dried overnight in a vacuum oven at 50°C.
• PMMA-b- P(EHMA-stat-MMA) with targeted degree of polymerization (DP) 100 at 10% w/w solids is representative and conducted as follows.
• PMMA-CPADB (0.2624 g; 0.04 mmol
• 1,3,5-trioxane 0.0477 g; 0.53 mmol
• EtOH 6.3120 g
• milli-Q water 2.0 g
• the solution was stirred in a preheated oil bath at 70 °C for 10 min.
• BzMA (0.4603 g, 2.6 mmol)
• PMMA-CPADB macroRAFT agent 0.4650 g, 0.065 mmol
• AIBN 5.4 mg, 0.033 mmol
• 10 ml of EtOH/water mixture 80/20 by volume
• the mixture was purged with nitrogen gas for 30 min in an ice bath before placing in an oil bath at 70°C with magnetic stirring. After 18 h, the polymerization was stopped by removing from the oil and opened to the air.
• the monomer conversion was determined to be ⁇ 98% via 1 H NMR in d 6 -DMSO.
• the as-synthesized block copolymers were analyzed by TEM/SEM.
• Polymeric nanofibers comprising hydrophobic corona and core were synthesized via dispersion polymerization of hydrophobic monomers in EtOH and water mixture. Block polymers self-assembled to nanofibers and the morphologies were confirmed by TEM/SEM (Fig.12).
• Scheme SI-1 RAFT dispersion polymerization of hydrophobic monomer(s) in the presence of PMMA macroRAFT agent.

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