GB1215320A - Production of acrylonitrile polymers using a redox catalyst system - Google Patents

Abstract

1,215,320. Preparation of acrylonitrile polymers. MONSANTO CO. 19 Dec., 1967 [29 Dec., 1966], No. 57640/67. Heading C3P. A process for preparing acrylonitrile polymers in an aqueous polymerization system comprises feeding acrylonitrile-containing monomer into the system and using as the polymerization catalyst a redox system containing a watersoluble sulphoxy reducing agent, said redox system being partially decomposed before being introduced into the polymerization system. The process may be effected continuously or batchwise, and the pH of the polymerization system is preferably maintained between 2 and 4. The monomer may consist solely of acrylonitrile or may include one or more comonomers, e.g. acrylic, methacrylic or chloroacrylic acid or an ester thereof, a vinyl or vinylidene halide, 1 .chloro- 1 -bromoethylene, methacrylonitrile, (meth)acrylamide or chloroacrylamide or an alkyl derivative thereof, methyl vinyl ketone, a vinyl carboxylate, e.g. vinyl acetate, a vinyl-imide, an ester of methylene malonic acid, an unsaturated dicarboxylic acid or an anhydride or ester thereof, a vinyl-heterocyclic compound, an alkyl vinyl ether, vinyl sulphonic acid, styrene or vinyl naphthalene. The oxidizing component of the redox system is suitably a perborate, perchlorate, persulphate or persulphuric acid; the reducing component may be sulphur dioxide or an alkali metal bisulphite or metabisulphite, and may optionally also include iron.