Abstract: Provided is a molding composition comprising, based on the total weight of the composition, (A) 50.0% by weight to 99.5% by weight of at least one (co)polymer which is a homopolymer or copolymer of at least 80% by weight of methyl methacrylate, (B) 0.5% by weight to 50.0% by weight of at least one copolymer obtained by polymerization of a monomer, and (C) at least one low molecular weight (meth)acrylate (co)polymer having a solution viscosity in chloroform at 25° C. (ISO 1628—part 6) of less than or equal to 55 ml/g.

Abstract: A polymer composition comprising star macromolecules is provided. Each star macromolecule has a core and five or more arms, wherein the number of arms within a star macromolecule varies across the composition of star molecules. The arms on a star are covalently attached to the core of the star; each arm comprises one or more (co)polymer segments; and at least one arm and/or at least one segment exhibits a different solubility from at least one other arm or one other segment, respectively, in a reference liquid of interest.

Abstract: The present invention is directed to a method of increasing the green strength of a rubber composition, comprising the step of combining in the rubber composition, a copolymer comprising: a polymeric backbone chain comprising a diene based elastomer selected from the group consisting of solution polymerized styrene butadiene rubber, emulsion polymerized styrene butadiene rubber, natural polyisoprene rubber, synthetic polyisoprene rubber, and polybutadiene; and polymeric sidechains bonded to the backbone chain, the sidechains comprising a polymer derived from an N-substituted monoalkyl acrylamide.

Abstract: A film of poly(trimethylene arylate) and a polystyrene wherein the polystyrene concentration is in the range of 0.5 to 40 weight %. Poly(trimethylene terephthalate) and polystyrene are particularly useful. Also, disclosed are processes for preparing the film.

Abstract: A sizing composition comprises a blend of at least two anionic copolymers.

Abstract: Disclosed herein is a thermoplastic resin composition having excellent scratch resistance and a method for preparing the same. The thermoplastic resin composition comprises (A) about 80 to about 95% by weight of a terpolymer of (meth)acrylic acid alkyl ester-aromatic vinyl-cyanide vinyl compound; and (B) about 5 to about 20% by weight of a butadiene rubber.

Abstract: Polyolefin based sealing element compositions with good oxygen barrier properties particularly suitable for forming sealing elements, for example gaskets and cap liners that are especially useful for sealing containers having products such as liquids or food-stuffs therein. The compositions when formed as sealing elements do not appreciably contribute taste and/or odor to a packaged product including the sealing element. The compositions have desirable rheological properties and are thus readily processable at various temperatures.

Abstract: A block copolymer or graft copolymer with weight-average molar mass Mw of at least 100 000 g/mol, comprising a) at least one block S composed of from 95 to 100% by weight of vinylaromatic monomers and from 0 to 5% by weight of dienes, and b) at least one copolymer block (S/B)A composed of from 63 to 80% by weight of vinylaromatic monomers and from 20 to 37% by weight of dienes, with glass transition temperature TgA in the range from 5 to 30° C., where the proportion by weight of the entirety of all of the blocks S is in the range from 50 to 70% by weight, based on the block copolymer or graft copolymer, and also mixtures thereof, and their use.

Abstract: Disclosed is the preparation of compositions which are blends of certain types of hydrogenated ethylene-dicyclopentadiene (E/DCPD) copolymers in combination with elastomeric polymers. An E/DCPD copolymer and an elastomeric polymer are co-dissolved in a common liquid reaction medium which is then subjected to hydrogenation conditions. These hydrogenation conditions serve to hydrogenate in-situ at least a portion of the residual double bonds of the E/DCPD copolymer component and possibly also eliminate any residual unsaturation which might be present in the elastomeric polymers. This combination of materials which has been hydrogenated in-situ can then be co-precipitated to form a polymer composition which can be molded into polyolefin materials of improved structural, thermal and mechanical properties with desirable impact resistance.

Abstract: Provided is a resin composite material in which a carbon material with a graphene structure is dispersed in a synthetic resin and which has a high mechanical strength and a low linear expansion coefficient and a method for producing the resin composite material. A resin composite material contains a synthetic resin and a carbon material with a graphene structure dispersed in the synthetic resin, wherein the synthetic resin is grafted onto the carbon material and the grafting ratio thereof onto the carbon material is 5% to 3300% by weight. A method for producing a resin composite material includes the steps of: preparing a resin composite containing a synthetic resin and a carbon material with a graphene structure dispersed in the synthetic resin; and grafting the synthetic resin onto the carbon material concurrently with or after the step of preparing the resin composite.

Abstract: The present invention provides a thermoplastic resin composition which comprises (A) a (meth)acrylic acid alkyl ester-based polymer forming a network-shaped disperse phase; and (B) an aromatic vinyl-cyanide vinyl based copolymer forming a continuous phase. The thermoplastic resin composition of the present invention can have an excellent low gloss characteristics while maintaining basic physical properties of a weather resistance, impact strength, thermal resistance, and delamination characteristics.

Abstract: This invention relates to the preparation of thermoplastic vulcanizates (TPVs) with unique morphological features, more specifically, this invention relates to a method for preparing TPV compositions wherein the mixing of plastomers and elastomers are carried out in solvent with curatives to induce cross-linking.

Abstract: Interpolymer resin particles that include from about 20% to about 60% by weight based on the weight of the particles of uncross-linked polyolefin resin particles having a VICAT softening temperature greater than 85° C. and from about 40% to about 80% by weight based on the weight of the interpolymer particles of polymerized vinyl aromatic monomer composition particles that have been polymerized in the uncross-linked polyolefin resin particles to form an interpenetrating network of polyolefin resin particles and polystyrene particles. The interpolymer resin particles have a gel content ranging from about 0 to about 1.5% by weight based on the weight of the interpolymer resin particles, a VICAT softening temperature ranging from about 90° C. to about 115° C., and a melt index value ranging from about 0.2 to about 35.0 g/10 minutes (Condition G).

Abstract: There is provided a shoe sole component that has properties such as strength and cushioning property that are suppressed from being changed even under a wide temperature range from severe cold at ?10° C. or lower to high temperature conditions exceeding 30° C. A shoe sole component includes a cross-linked foam of a resin composition, the resin composition containing a thermoplastic polyolefin resin, in which tan ? (?20° C. to 40° C.) at a frequency of 10 Hz measured according to JIS K 7244-4 is 0.01 to 0.5, and tan ? (?20° C.)/tan ? (40° C.) at a frequency of 10 Hz is 0.7 to 1.3.

Abstract: The present invention comprises a molding composition comprising at least about 70% wt. polypropylene or polypropylene random copolymer; up to about 30 wt. % of a block copolymer composition comprising at least one selectively hydrogenated block copolymer which substantially matches the index of refraction of the polypropylene or polypropylene random copolymer, and up to about 0.70% by wt. of a clarifying agent, wherein the weight % of the total blend is 100%. The present invention also may be a molded article produced from the molding composition. A molded article formed from such a composition at a thickness of 0.125 inches will have a haze of less than about 50% and an instrumented impact toughness of at least 100 inch-lbs at ?20° C. to ?30° C.

Abstract: The invention relates to the use of polyorganosiloxanes having 3 or more siloxane units, which has (i) at least one organic component R1, where R1 has at least one carbon-carbon multiple bond, and (ii) at least one hydrocarbon component R2, where R2 has a chain length of 5 to 50 carbon atoms. The polyorganosiloxanes are used in the processing and vulcanization of rubber and are incorporated reactively into it. They give rise to a lowering in the viscosity of the rubber in the course of processing and in some cases to an improvement in the mechanical properties of the vulcanized rubber.

Abstract: A thermoplastic elastomer composition which has excellent cleanability and is suitable for use as a medical rubber supply. It is characterized by comprising a rubber ingredient dynamically crosslinked with a crosslinking agent and a matrix which comprises a thermoplastic resin and in which the crosslinked rubber ingredient has been dispersed, the crosslinking agent comprising a triazine derivative.

Abstract: A dynamically vulcanized alloy contains at least one isobutylene-containing elastomer and at least one thermoplastic resin, wherein the elastomer is present as a dispersed phase of small particles in a continuous phase of the thermoplastic resin. The elastomer in the alloy is cured by means of a cure system comprising an increased amount of curative and preferably with no cure accelerators present in the cure system. The elastomer obtains at least seventy five percent cure in not more than 15 minutes at temperatures 220° C. or greater.

Abstract: Thermoplastic elastomer, which comprises a fumed, hydrophilic or hydrophobic silica, which has been structurally modified and also a process for the improvement of the mechanical properties of thermoplastic elastomers. The thermoplastic elastomers are produced by preparing a masterbatch from the components (e.g. thermoplastic resin component and fumed silica) and compounding this with further thermoplastic elastomers.

Abstract: The present invention is directed to a vulcanizable rubber composition comprising: a diene based elastomer; and a compound of formula I where Q is an n-valent organic group of 1 or more carbon atoms and optionally one or more of nitrogen, oxygen, sulfur, halogen, silicon, and phosphorus atoms; X is a divalent polymer group capable of exhibiting a lower critical solution temperature; R is independently a hydrogen atom or a monovalent group of formula (II) where Z is a monovalent organic group of 1 or more carbon atoms and optionally one or more of nitrogen, oxygen, sulfur, halogen, silicon, and phosphorus atoms; and n is an integer greater than or equal to 2. The invention is further directed to a rubber composition comprising the reaction product of a diene based elastomer and a compound of formula I, and a pneumatic tire with a tread comprising the rubber composition.

Abstract: We disclose a monovinylarene-conjugated diene block copolymer containing a plurality of monovinylarene-conjugated diene mixed blocks, wherein each mixed block contains conjugated diene units and monovinylarene units in a weight ratio of about 0.05 to about 0.33. We also disclose a composition containing (a) from about 50 parts by weight to about 95 parts by weight of the monovinylarene-conjugated diene block copolymer and (b) from about 5 parts by weight to about 50 parts by weight of polystyrene; wherein the monovinylarene-conjugated diene block copolymer and the polystyrene total 100 parts by weight.

Abstract: A multilayer film for medical purposes is proposed, with one or two external layers, wherein the external layers contain: a first polyalphaolefin; a first thermoplastic elastomer with a melt viscosity of a melt flow index according to ISO 1133 of from 0.001 to 6 g/10 min at 230° C., 2.16 kg; and a second thermoplastic elastomer with a high melt viscosity not measurable according to ISO 1133 which is higher than the melt viscosity of the first thermoplastic elastomer.

Abstract: The present invention relates to an optical film comprising: a blended resin including 1) an acrylic copolymer resin containing an alkyl methacrylate monomer and a (metha) acrylic monomer containing an alicyclic or an aromatic ring, 2) a copolymer resin containing an alkyl methacrylate monomer, an aromatic vinyl monomer, and an acid anhydride monomer, and 3) a resin containing an aromatic or an alicyclic ring in the main chain of a polymer. The present invention also relates to a method for manufacturing the optical film, and a liquid crystal display device comprising the optical film. The optical film according to the present invention is excellent in heat resistance, optical transparency, mechanical strength, durability, and the like.

Abstract: A method of preparing a polystyrene blend that includes combining a first polystyrene composition having a first melt flow index with a second polystyrene composition having a second melt flow index and forming a polystyrene blend, the second melt flow index being at least 2 dg/min higher that the first melt flow index. The polystyrene blend has an observed tensile strength value greater than 3% above the expected tensile strength value. The second polystyrene composition can include a recycled polystyrene material, which can include expanded polystyrene. An alternate method of preparing the polystyrene blend includes combining a polystyrene composition with a styrene monomer to form a reaction mixture, polymerizing the reaction mixture and obtaining a polystyrene blend, where the polystyrene containing composition has a melt flow index at least 2 dg/min higher than the melt flow index of the styrene monomer after it has been polymerized.

Abstract: A method of making a styrenic composition having a high melt strength including combining a styrenic monomer and a second monomer to form a combined mixture and subjecting the combined mixture to polymerization to obtain a styrenic co-polymer, wherein the second monomer comprises a hydroxyl functional group and wherein the styrenic composition has a greater melt strength than that of general purpose polystyrene.

Abstract: Disclosed herein is a non-glossy rubber modified aromatic vinyl-vinyl cyanide copolymer and a method for continuously preparing the same. The copolymer comprises about 80 to about 93% by weight of an aromatic vinyl-vinyl cyanide copolymer grafted onto about 7 to about 20% by weight of a diene-based rubber, and a dispersed phase of the copolymer has an average rubber particle diameter of about 6 to about 20 ?m and a span of about 1.2 to about 2.8.

Abstract: The present invention relates to a tire having a tread comprising a rubber composition that comprises at least: as a first diene elastomer, between 5 and 25 phr of a styrene-nitrile-butadiene terpolymer (SNBR) having a nitrile monomer content between 4 and 18% by weight; a second diene elastomer other than SNBR; a reinforcing filler; a liquid plasticizer, the glass transition temperature of which is below ?20° C. The invention makes it possible to improve the properties of rolling resistance and of grip on wet ground of tire treads.

Abstract: A process for the preparation of vinylaromatic (co)polymers grafted on an elastomer comprising a rigid matrix consisting of vinylaromatic polymers or copolymers and of an elastomeric phase dispersed in the matrix in form of particles with a strictly bimodal distribution which comprises the functionalization of a first elastomeric fraction by means of a catalytic system containing a stable free radical initiator and subsequently the polymerization of the thus obtained mixture also in presence of a second non functionalized elastomeric fraction.

Abstract: Thermoplastic vulcanizate elastomer obtained by dynamic vulcanization of a heterophasic polyolefin composition in presence of at least (i) an alkenyl-substituted alkoxysilane grafting agent and (ii) water; wherein said heterophasic polyolefin composition has flexural modulus equal to or lower than 150 MPa, and comprises: (a) a crystalline propylene homopolymer or copolymer of propylene with up to 15% of ethylene or other alpha-olefin comonomer(s), or their combinations, and (b) a copolymer or a composition of copolymers of ethylene with other alpha-olefins, containing from 15% to 40% of ethylene, said thermoplastic vulcanizate elastomer having compression set values in the range from 45-65%, the ratio of elongation at break to compression set values over 10 and hardness shore A values below 90.

Abstract: The present invention provides a propylene polymer composition having excellent transparency, flexibility, heat resistance, scratch resistance and rubber elasticity with a good balance. The propylene polymer composition comprises 1 to 40 parts by weight of isotactic polypropylene (i) and 60 to 99 parts by weight of a propylene/ethylene/?-olefin copolymer (ii) which contains 45 to 89% by mol of a propylene component, 10 to 25% by mol of an ethylene component, and optionally, 0 to 30% by mol of constituent units (a) derived from an ?-olefin of 4 to 20 carbon atoms.

Abstract: A cationically polymerizable composition comprising (i) a cationically polymerizable resin, (ii) an onium salt, (iii) an azo or peroxide initiator, exhibits a lower cure temperature upon the addition of (iv) a catalytic or substoichiometric amount of an electron-rich vinyl resin to the reaction.

Abstract: This invention relates to a rubber composition capable of using in a tread rubber of a tire to improve both an initial gripping performance and a running stability of the tire as compared with those of conventional tires, and more particularly to a rubber composition formed by compounding an indene-containing C9-based resin having a softening point of 130° C.-190° C. and an indene content of 30-80 mass % into a rubber component.

Abstract: The present invention relates to an adhesive composition comprising a mixture of multi-block copolymers, in particular, an adhesive composition comprising a block copolymer represented by Formula 1, a hydrocarbon adhesive resin and a plasticizer. The adhesive composition according to the present invention can be easily processed due to its low melting point and shows improved adhesive properties such as loop tack, 180° peel strength and holding power.

Abstract: A water redispersible polymer powder is produced by drying an aqueous mixture of a high Tg carboxylated styrene butadiene polymer and a low Tg carboxylated styrene butadiene polymer, where the ratio of the mean or average particle size of the high Tg polymer to the particle size of the low Tg polymer is from 1:1 to 5:1, preferably from 1:1 to 3:1, and the amount of the high Tg polymer is from 20 wt. % to 35 wt. %, preferably from 25 wt. % to 30 wt. %, based upon the total weight of the high Tg polymer and the low Tg polymer. Cement compositions such as mortars, which contain the redispersible polymer powder exhibit unexpectedly superior high bond strength and high impact resistance.

Abstract: A film containing a polymer composition that includes from 0.1 to 60% by weight of interpolymer resin particles containing a styrenic polymer intercalated within a first polyolefin and from 40 to 99.9% by weight of at least one second polyolefin. The first polyolefin is present at from 20% to 80% by weight based on the weight of the particles, has a VICAT softening temperature greater than 60° C. and a melt index of from 0.3 to 15 g/10 minutes (Condition I, 190° C., 2.16 kg). The styrenic polymer is present at from 20% to 80% by weight based on the weight of the particles. The interpolymer resin particles have a gel content ranging from 0 to 5% by weight based on the weight of said interpolymer resin particles, a VICAT softening temperature ranging from 85° C. to 115° C., and a melt index value ranging from 0.1 to 6.0 (Condition I).

Abstract: The invention provides for processes to produce elastomeric compositions, the processes including contacting at least one elastomer with a processing aid, wherein the processing aid comprises at least one functionalized polymer having at least one halogen group. The invention also provides for articles such as innerliners for tires produced from the aforementioned elastomeric compositions.

Abstract: A method of preparing a polystyrene blend that includes combining a first polystyrene composition having a first melt flow index with a second polystyrene composition having a second melt flow index and forming a polystyrene blend, the second melt flow index being at least 2 dg/min higher that the first melt flow index. The polystyrene blend has an observed tensile strength value greater than 3% above the expected tensile strength value. The second polystyrene composition can include a recycled polystyrene material, which can include expanded polystyrene. An alternate method of preparing the polystyrene blend includes combining a polystyrene composition with a styrene monomer to form a reaction mixture, polymerizing the reaction mixture and obtaining a polystyrene blend, where the polystyrene containing composition has a melt flow index at least 2 dg/min higher than the melt flow index of the styrene monomer after it has been polymerized.

Abstract: A macromolecule including a polymer and a polyhedral radical chemically bonded to a terminus of the polymer provides numerous processing and performance advantages. Further functionalization of this macromolecule also is described as being advantageous in certain circumstances. Methods of providing, functionalizing, and utilizing the macromolecule also are provided.

Abstract: Composition containing, based in each case on its total weight, A) 50.0% by weight to 99.5% by weight of at least one (meth)acrylate (co)polymer and B) 0.5% by weight to 50.0% by weight of at least one copolymer obtainable by polymerization of a monomer mixture comprising i. 70% by weight to 92% by weight of a vinylaromatic monomer and ii. 8% by weight to 30% by weight of acrylonitrile or methacrylonitrile or mixtures thereof and iii. 0% by weight to 22% by weight of at least one further monomer, the composition having a haze according to ASTM D1003 of less than 2.0% at 23° C. and a haze according to ASTM D1003 of less than 4.0% at 40° C. and the composition containing at least one (meth)acrylate (co)polymer a) having a solution viscosity in chloroform at 25° C. (ISO 1628—part 6) of greater than 55 ml/g. The moldings obtainable from the composition are distinguished in particular by improved stress cracking resistance and are suitable in particular for coverings, finishes or films.

Abstract: Disclosed herein is a polymeric composition comprising a polymeric composition comprising a first crosslinked network; and a second crosslinked network; wherein the first crosslinked network is crosslinked at a first stress and/or a first strain and the second crosslinked network is crosslinked at a second stress and/or a second strain; where the first stress and/or the first strain is different from the second stress and/or the second strain either in magnitude or direction. Disclosed herein is a method comprising subjecting a polymeric mass to a first stress and/or a first strain level; crosslinking the polymeric mass to form a first crosslinked network; subjecting the polymeric mass to a second stress and/or a second strain level; and crosslinking the polymeric mass to form a second crosslinked network; where the first stress and/or the first strain level is different from the second stress and/or the second strain level.

Abstract: A weather resistant thermoplastic resin having excellent low gloss characteristics according to the present invention comprises a (meth)acrylic acid alkyl ester-based polymer (A) and an aromatic vinyl-cyanide vinyl based copolymer (B), wherein the (meth)acrylic acid alkyl ester-based polymer (A) forms a network-shaped disperse phase, and the aromatic vinyl-cyanide vinyl based copolymer (B) forms a continuous phase. The thermoplastic resin has excellent low gloss characteristics as well as superior weatherability, impact resistance, thermal resistance, delamination characteristics, and the like.

Abstract: The present invention provides functionalized styrene oligomers and polymers prepared by Friedel-Crafts chemistry, as well as epoxidation products thereof. In particular, the invention provides allyl functional TPE. The invention also provides methods for making the functionalized styrene oligomers and polymers of the invention as well as epoxidation products thereof, compositions containing the same, and methods for using the functionalized and epoxified styrene oligomers that take advantage of the unique properties of the compounds and compositions of the invention.

Abstract: A partly cross-linked thermoplastic elastomer polyolefin composition intended to be converted by any plastics processing technique into a molded part, such as a cover for housing a vehicle's safety airbag, comprises an olefin polymer of polypropylene type, at least one copolymer of ethylene-alpha-olefin type, at least one cross-linking agent and a free radicals formation agent characterized in that a) the olefin polymer of polypropylene type is chosen from the group of polypropylene/ethylene or polypropylene/?-olefin copolymers and selected from those having an impact resistance of at least 40 kJ/m2 when measured using the notched Izod impact resistance test at 23° C. in accordance with ISO standard 180. b) at least one copolymer of the ethylene-?-olefin type is selected from the group formed by those having a density at least equal to 0.870 g/cm3 in accordance with ISO standard 1183. c) at least one thermoplastic elastomer is introduced into the composition.

Abstract: A heat-shrinkable film. The film comprising at least one layer having at least one propylene-based polymer comprising 60 wt % to 98 wt % propylene derived units and 2 wt % to 40 wt % one or more other alpha olefins, the propylene-based polymer having: a triad tacticity of 70% or more, a heat of fusion of less than 80 J/g, a weight average molecular weight (Mw) as measured by GPC of from 70,000 to 250,000. The layer also comprises at least one thermoplastic resin and at least one hydrocarbon resin.

Abstract: A fluidity-improving agent containing 0.5 to 99.5 parts by mass of a polymer (A) which is obtained by polymerizing a monomer mixture (a) containing 0.5 to 99% by mass of (a1) an aromatic vinyl monomer, 0.5 to 99% by mass of (a2) a phenyl(meth)acrylate or a phenyl(meth)acrylate containing a substituent in a phenyl group, and 0.5 to 5% by mass of (a3) a vinyl monomer including a functional group (X), and 0.5 to 99.5 parts by mass of a polymer (B) which is obtained by polymerizing a monomer mixture (b) containing (b1) a phenyl(meth)acrylate or a phenyl(meth)acrylate containing a substituent in a phenyl group with a compound including a functional group (Y) reactive with the functional group (X), where the total of the polymer (A) and the polymer (B) is 100 parts by mass.

Abstract: Provided is a decomposition method of an aromatic block copolymer, wherein the aromatic block copolymer comprises a segment 1 represented by the following general formula (1) and a segment 2 comprising a structural unit represented by the following general formula (2) and/or a structural unit represented by the following general formula (3), and the segment 2 is subjected to chemical decomposition.

Abstract: The present invention relates to a composition comprising thermoplastic materials and crosslinked microgels which are not crosslinked by high-energy radiation, processes for its preparation, its use for the production of thermoplastically processable shaped articles and shaped articles produced from the composition.

Abstract: A method of modifying the rheology of a thermoplastic resin that includes the steps of providing a thermoplastic resin and blending interpolymer resin particles with the thermoplastic resin. The interpolymer resin contains a styrenic polymer intercalated within a polyolefin, such that the thermoplastic resin is present as a continuous phase and the interpolymer resin is present as a dispersed phase. The method provides a rheology modified thermoplastic resin with improved physical characteristics.

Abstract: Elastomeric films which are both soft and thermally, UV and oxidatively stable are provided. The films are composed of coupled, selectively hydrogenated block copolymers having a relatively high molecular weight and high vinyl content. In addition to the block copolymer other components may be present in formulated films such as other block copolymers, hydrocarbon resins, polyolefins, metallocene polyolefins, homopolystyrene or mineral oils. The softness of the films is determined by the stress at 100% tensile elongation where the films with suitable softness have a 100% stress of about 100 psi or less. While soft, the films also are strong with tensile strengths of 1000 psi or more and suitable hysteresis properties. The elastomeric films are useful as integral components of personal hygiene articles such as gloves, diapers, incontinence products, disposable swimwear and disposable undergarments.

Abstract: The present invention relates to a method of forming polymer on the surface of polymer particles, the method comprising: (i) providing a dispersion comprising a continuous aqueous phase, a dispersed organic phase comprising one or more ethylenically unsaturated monomers, and a RAFT agent as a stabiliser for said organic phase; (ii) polymerising the one or more ethylenically unsaturated monomers under the control of the RAFT agent to form an aqueous dispersion of seed polymer particles; (iii) crosslinking the seed polymer particles; (iv) swelling the crosslinked seed particles with one or more ethylenically unsaturated monomers to form an aqueous dispersion of monomer swollen crosslinked seed polymer particles; (v) increasing the temperature of the monomer swollen crosslinked seed polymer particles to expel at least some of the monomer therein onto the surface of the particles; and polymerising at least the expelled monomer to form polymer on the surface of the particles.