Abstract: A method for inhibiting the formation of undesired polymer accumulations during distillative purification of vinylaromatic monomers such as styrene, alpha-alkylstyrene, vinyltoluene, divinylbenzene or the like comprising distilling the vinylaromatic monomer in the presence of a cupreous material such as metallic copper or a copper alloy, and apparatus for carrying out the method in which at least a portion of the interior of a distillation column used to purify vinylaromatic monomer, particularly in areas where there is little vapor movement, is provided with a surface layer or coating of cupreous material.

Abstract: A continuous mass polymerization process for preparing rubber reinforced styrenic copolymers comprising forming a solution in an inert solvent of a styrenic polymer matrix and a monomer material capable of polymerizing to form a cross-linked rubbery polmyer, continuously charging the solution into a polymerization reactor and subjecting the solution to mass polymerization conditions whereby there is formed in situ a cross-linked rubbery polymer dispersed in the styrenic polymer matrix, continuously withdrawing the reaction mixture from the polymerization reactor and recovering the resulting rubber reinforced styrenic copolymer.

Abstract: A continuous process for preparing rubber reinforced resins which are copolymers of styrenic compound, acrylonitrile and diolefinic compound.

Abstract: A continuous process for polymerizing a monomer mixture of acrylate and diolefinic compound in the presence of a copolymeric matrix of styrene and acrylonitrile.

Abstract: A process for preparing styrenic resins is disclosed which comprises the steps of:(a) adding monomer material selected from the group consisting of monomers and monomer mixtures being capable of forming a rubbery polymer by polymerization and preferably comprising an acrylic acid ester to a polymeric matrix comprising a polymer of a styrenic compound;(b) contacting the polymeric matrix and the monomer material under conditions in which said monomer is absorbed by said polymeric matrix; and(c) polymerizing said monomer material with formation of a rubbery polymer partly grafted on the polymeric matrix.The resulting styrenic resin exhibits good impact strength and gloss.

Abstract: An improved process for preparing rubber reinforced styrenic resins which are composite systems containing a copolymer of styrene and unsaturated nitrile together with copolymers of acrylates and conjugated diolefins.

Abstract: Disclosed is a process for the production of rubber-modified styrene copolymers, particularly high rubber content styrene copolymers, such as high rubber content ABS polymers, by suspension polymerization, comprising suspension polymerizing an admixture of polymerizable materials comprising styrene monomer, rubber polymer, and optional additional monomers copolymerizable therewith; and melt extruding the resultant rubber-modified styrene copolymer under extrusion conditions having a shear force sufficient to homogeneously disperse the rubber phase throughout the copolymer. Through the use of the process of the instant invention, high rubber content styrene copolymers may be produced in a single suspension step, with impact properties and surface appearance comparable to copolymers produced in the conventional two-step polymerization process.

Abstract: Disclosed is a process for the production of ABS resins comprising the steps of (a) imbibing a stabilized latex of a rubbery polymer with styrene in an amount of about 1.5 and 15 parts by weight per 100 parts of dry latex and with acrylonitrile in an amount of about 5 to 15 parts by weight per 100 parts of dry latex; (b) introducing the imbibed latex into a polymerization vessel; (c) introducing into the polymerization vessel a mixture of styrene, acrylonitrile and a free radical initiator; (d) introducing a polymerization activator into the polymerization vessel; (e) polymerization the styrene and acrylonitrile in the polymerization vessel in the presence of the latex, whereby an ABS graft copolymer is produced; and (f) withdrawing the ABS polymer from the polymerization vessel.

Abstract: A composition obtained by mixing polystyrene with a master-batch composition containing a mixture of a vinyl aromatic polymer, a rubbery dienic polymer and a sequenced copolymer of styrene and diene, the total styrene polymer content of this master-batch composition including both the free polystyrene and the polystyrene present in the sequenced copolymer, being between 50 and 80% by weight of the composition, the total rubber content of this master-batch composition, including both the rubbery dienic polymer and the dienic polymer present in the sequenced copolymer being between 20 and 50% by weight of the composition, the sequenced copolymer content being such that it introduces from 3 to 90% by weight of the total rubber in the composition, the total percent rubber content of said master-batch composition being at least 1.5 times the total percent rubber content of the final composition.

Abstract: Disclosed is a process for producing expandable beads of vinyl aromatic polymer resin which provide cellular materials having a smaller and more uniform cell size, comprising the steps of suspension polymerizing beads of the vinyl aromatic polymer resin, and impregnating the beads while in suspension with a liquid blowing agent in the presence of an emulsifier comprising a diethanolamide of a fatty acid containing from 12 to 20 carbon atoms, and having a hydrophilic-lipophilic balance lower than 15.

Abstract: A composition comprising a mixture of a styrene polymer, a rubbery dienic polymer and a sequenced copolymer of styrene and a diene, the total styrene polymer content which includes the free polystyrene and the polystyrene present in the sequenced copolymer is between 50 and 99% by weight of the composition, the total rubber content, which include the rubbery dienic polymer and the dienic polymer present in the sequenced copolymer, is between 1 and 50% by weight of the composition, the amount of sequenced copolymer being such as to bring to the composition from 3 to 90% by weight of the total rubber in the composition.

Abstract: A process for producing ABS resins by copolymerizing a mixture of a styrenic compound and an unsaturated nitrile selected from the group consisting of acrylonitrile and methacrylonitrile, in the presence of an elastomer, by a two-step process comprising a mass copolymerization step and then a suspension copolymerization step, said process comprising carrying out the mass copolymerization step in the presence of p-chlorobenzoyl peroxide as an initiator and dithiobis(benzothiazole) as a chain transfer agent.

Abstract: A high molecular weight polymer characterized by chains of benzene rings comprising alternatively di-substituted rings and tri-substituted rings, wherein the di-substituted rings comprise a major part of 1,3 (meta)- and a minor part of 1,4 (para)- di-substituted rings, and the tri-substituted rings are members of the group consisting of 1,3,5-, 1,2,4- and mixtures of 1,3,5- and 1,2,4- tri-substituted rings, these tri-substituted rings being substituted by 1 to 3 chains of benzene rings, each of the other substituents being a benzene ring which is unsubstituted or is substituted by a radical of the group consisting of alkyl, aryl and halogen radicals.

Abstract: A process for producing a copolymer of styrene and acrylonitrile substantially free of acrylonitrile which comprises copolymerizing styrene and acrylonitrile, and optionally in the presence of an elastomer, and treating the resulting copolymer with an aqueous solution of a sulphur compound selected from the group consisting of alkaline sulfides and alkaline disulfides.

Abstract: A process for producing a copolymer of styrene and acrylonitrile substantially free of acrylonitrile which comprises copolymerizing styrene and acrylonitrile and treating the resulting copolymer with an aqeuous solution of a sulphur compound selected from the group consisting of alkaline sulfides and alkaline disulfides.

Abstract: Disclosed is a process for the preparation of high-impact vinyl aromatic polymers by mass pre-polymerizing a vinyl aromatic hydrocarbon in the presence of a rubber, and suspension polymerizing the mass pre-polymer in the presence of hydroxyapatite and at least one ethoxysulphate of the formula RO (C.sub.2 H.sub.4 O).sub.x SO.sub.3 M, wherein R is an alkyl radical containing from 10 to 16 carbon atoms, x is from 2 to 6, and M is Na, K, N, NH.sub.4, an amine group, or an alkanol amine group.