Abstract: Copolymer beads made by suspension copolymerization of styrenic monomer with divinylbenzene under conditions such that the products had defined solubility, gel content, molecular weight and bead size characteristics which enabled their use (after impregnation with a blowing agent and pre-expansion) in molding into foamed cups over a much broader range of time and temperature and the resultant cups are stiffer per given weight than cups made from conventional polystyrenes utilized for making foamed cups. These advantages are realized without any sacrifice in cup appearance.

Abstract: Copolymer beads made by suspension copolymerization of styrenic monomer with divinylbenzene under conditions such that the products had defined solubility, gel content, molecular weight and bead size characteristics which enabled their use (after impregnation with a blowing agent and pre-expansion) in molding into foamed cups over a much broader range of time and temperature and the resultant cups are stiffer per given weight than cups made from conventional polystyrenes utilized for making foamed cups. These advantages are realized without any sacrifice in cup appearance.

Abstract: Expandable styrene polymer particles which have anti-static and anti-lumping properties during expansion are produced by adding 0.1 to 0.4 parts of alkyl and alkylaryl ethers of polyethoxyethanol mono- and diesters of phosphoric acid per 100 parts of polymer particles during impregnation of the polymer particles with blowing agents. The esters may be added as sole antistatic agent or in addition to the known internal additives which impart fast-cool and antilump properties.

Abstract: Expandable styrene polymer particles which have anti-stratification and anti-lumping properties during expansion are produced by dry blending styrene polymer particles in the presence of 0.01-0.04 parts of alkyl and alkylaryl ethers of polyethoxyethanol mono- and diesters of phosphoric acid per 100 parts of polymer particles. The esters may be added as sole anti-stratification or anti-lumping agent or in addition to known anti-lumping agents.

Abstract: Expandable styrene polymer particles which have anti-static and anti-lumping properties during expansion are produced by adding 0.1 to 0.4 parts of alkyl and alkylaryl ethers of polyethoxyethanol mono- and diesters of phosphoric acid per 100 parts of polymer particles during impregnation of the polymer particles with blowing agents. The esters may be added as sole antistatic agent or in addition to the known internal additives which impart fast-cool and anti-lump properties.

Abstract: Expandable styrene polymer particles which have anti-stratification and anti-lumping properties during expansion are produced by dry blending styrene polymer particles in the presence of 0.01-0.04 parts of alkyl and alkylaryl ethers of polyethoxyethanol mono- and diesters of phosphoric acid per 100 parts of polymer particles. The esters may be added as sole anti-stratification or anti-lumping agent or in addition to known anti-lumping agents.

Abstract: The absorption of water by styrene/maleic anhydride copolymer particles during the impregnation of the particles in aqueous suspension is greatly reduced by the addition of salt to the impregnation system.This process produces expandable particles of non-equimolar copolymers of styrene and maleic anhydride having considerable less heterogeneity, finer cell structure, greater expandability, less heat sensitivity, less shrinkage, and lower density potential on molding.

Abstract: Coated beads which exhibit anti-lumping properties upon pre-expansion and which are useful in the formation of soft expanded articles are prepared by coating initial polystyrene beads, in suspension, with a coating composition comprising styrene and a macromonomer of styrene and isoprene or styrene and butadiene, the coating compositions added to the suspension as an aqueous emulsion containing a catalyst and a polyoxyethylene ether of nonylphenol or octylphenol as surfactant.

Abstract: Styrenic polymer expandable beads that are useful in forming heat-resistant foamed articles are prepared by forming an aqueous suspension of initial styrenic polymer beads and adding thereto a portion of a comonomer solution of styrenic monomer and methacrylic acid, which solution also contains a polymerization regulator, forming an emulsion of catalyst, monomer solution and polyvinyl alcohol suspending agent, adding portions of the emulsion to the suspension and then adding the remainder of the comonomer solution to the suspension, and the suspension with added monomers is heated to copolymerize the styrenic monomer and methacrylic acid about the initial beads and form a coating about the beads.

Abstract: Styrenic polymer beads of a preferred size are produced from styrenic polymer beads of a smaller size by forming an aqueous suspension of the styrenic polymer beads and adding thereto, under polymerization conditions, an aqueous emulsion formed by admixing styrenic monomer and a catalyst therefor with water containing a nonionic surfactant that is an ethylene oxide condensate of an alkylphenol, which contains at least fifty moles of ethylene oxide per mole of alkylphenol. The beads of preferred size are formed without formation of fine styrenic polymer particles and without significant amounts of clusters of beads.

Abstract: Coated beads which exhibit anti-lumping properties upon pre-expansion and which are useful in the formation of soft expanded articles are prepared by coating initial polystyrene beads, in suspension, with a coating composition comprising styrene and a macromonomer of styrene and isoprene or styrene and butadiene, the coating compositions added to the suspension as an aqueous emulsion containing a catalyst and a polyoxyethylene ether of nonylphenol or octylphenol as surfactant.

Abstract: Polymeric beads for use in forming soft molded articles of low density are produced by formation of a plasticized elastomer-styrene polymeric coating about initial styrene beads, by forming an aqueous suspension of the initial beads, adding thereto an aqueous emulsion of a coating composition consisting of styrenic monomer, a conjugated diene elastomer, and a plasticizer, containing a catalyst and a nonionic surfactant comprising an ethylene oxide condensate of an alkylphenol, the surfactant containing at least thirty moles of ethylene oxide per mole of alkylphenol, and polymerizing the coating composition about the initial beads.

Abstract: Expandable styrene polymer particles are surface-coated with conjugated diene elastomers to prevent the particles from lumping together during expansion. The coating is applied by adding 0.05-0.25 part of conjugated diene elastomer to an aqueous suspension containing 100 parts of polymer particles during the impregnation of the mixture with a blowing agent.

Abstract: Fire-resistant foams having 1.2 to 2.5 pound per cubic foot density are prepared by coating 100 parts by weight of styrene polymer foam particles with at least 67 parts by weight of an intumescent paint and molding said coated prepuff into the desired end product foam.

Abstract: Attempts to prepare polystyrene by peroxide-initiated suspension polymerization at 125.degree. C resulted in polymer having narrower molecular weight distribution than desired. The problem has been solved by copolymerizing the styrene with from 0.05 to 0.35 weight per cent, based on styrene, of a modifying comonomer consisting of a non-conjugated diolefinic compound having one very reactive olefinic group and one less reactive olefinic group such as, for example, allyl methacrylate.