GB767642A - Production of styrene-type polymers - Google Patents

Abstract

Styrene, with or without compounds such as a -methyl styrene, vinyl toluene, acrylonitrile, ethyl and butyl acrylates, and methyl acrylate, is polymerized in the presence of an oily, unsaturated polymer of one or more conjugated diolefines having 4 to 6 carbon atoms, or copolymers with a lesser amount of mono-olefinic monomer. The oily polymers may be prepared from butadiene, isoprene, piperylene, dimethylbutadienes, methyl pentadienes, and chloroprene or mixtures thereof with minor proportions of styrene, a - and p-methyl styrenes, mono- and dichlorostyrenes, ethyl fumarate and maleate, methyl acrylate and methacrylate, methacrylonitrile and vinylidene chloride or with maleic anhydride, butadiene and styrene in a hydrocarbon solvent or diluent, e.g. benzene or heptane using an alkali metal catalyst, e.g. sodium; in aqueous emulsion in the presence of a sulphur-containing modifier, e.g. dodecyl mercaptan; in solution in heptane using hydrogen fluoride as catalyst; or in a diluent using cumene hydroperoxide as catalyst and carbon tetrachloride or di-isopropyl xanthogen disulphide as modifiers. The liquid polymer may be dissolved in the styrene and polymerized, en masse, if desired using catalysts such as hydrogen, benzoyl, t.-butyl and diacetyl peroxides, t.-butyl and cumene hydroperoxides, diethylperoxycarbonate, potassium persulphate, perborates, and a ,a 1 - azodiisobutyronitrile, p - bromobenzenediazonium fluoborate, N-nitrosoparabromoacetanilide, azomethane, phenyldiazonium halides, diazoaminobenzene, p-bromobenzenediazonium hydroxide and p-tolyl-diazoaminobenzene; in aqueous suspension using tricalcium phosphate or vinyl acetate-maleic anhydride as suspending agent; or in aqueous emulsion using a water-soluble salt of a sulphonated long-chain alkyl compound and conventional persulphate or redox catalyst systems. Interpolymerization to form a graft polymer may occur. Plasticisers, stabilizers, fillers, dyes, pigments or other polymers may be added to the products or may be present during the polymerization to give moulding compositions of increased toughness. U.S.A. Specifications 2,550,695, 2,581,094, 2,586,594 and 2,652,342 are referred to.