GB764296A - Improvements in the polymerisation of acrylonitrile - Google Patents

Abstract

Graft polymers are prepared by polymerizing in the presence of a polymerization catalyst a solution or dispersion of 60 to 90 per cent by weight of acrylonitrile and 10 to 40 per cent by weight of an isolated homopolymer or interpolymer of an amide of an alkenyl carboxylic acid which contains from 3 to 5 carbon atoms in the acid radical such as those derived from acrylamide, the N-monoalkyl and N:N-dialkyl substitution products of acrylamide and methacrylamide, itaconamide and its N-monoalkyl and N:N1-dialkyl substitution products in which the alkyl groups contain from 1 to 4 carbon atoms, citraconamide and its N-methyl and N-ethyl substitution products, alphachloracrylamide, alpha - chloro - N - methylacrylamide, and methyl and ethyl acetaminoacrylates. The amide interpolymers used are those obtained by polymerizing the above amides with one another or with monomers such as alkyl acrylates and methacrylates containing 1 to 4 carbon atoms in the alkyl group, vinyl acetate and propionate, styrene, alpha-methyl styrene, p-acetaminostyrene, alpha-acetoxystyrene, vinyl chloride, vinyl fluoride, vinyldene chloride, perfluoroethylene, ethyl vinyl and isopropyl vinyl ethers, vinyl methyl, vinyl ethyl, isopropenyl methyl and isopropenyl ethyl ketones, dimethyl, diethyl and diisopropyl maleates and fumarates, acrylic and methacrylic acids, acrylonitrile, methacrylonitrile, fumaronitrile, N-vinylphthalimide, ethylene, butadiene, and vinyl pyridines. Polymerization catalysts specified are peroxides such as benzoyl, acetyl, acetyl benzoyl, lauryl, oleoyl, triacetone and urea peroxides, tert.-butyl hydroperoxide, alkyl percarbonates, hydrogen peroxide, alkali metal perborates, alkali metal and ammonium persulphates which may be used in conjunction with an alkali metal bisulphite, and ketazines and azines. Polymerization may be carried out in an aqueous medium or in solution in a solvent such as acetonitrile or a mixture of water with acetone or acetonitrile. Aqueous polymerization media may contain emulsifiers such as sodium lauryl sulphate, sodium isobutylnaphthalenesulphonate, sodium 7 - ethyl - 2 - methylundecan - 4 - sulphonate, sulphonated ethers, alkali metal or amine addition salts of sulphosuccinic acid esters, alkali metal salts of fatty acids containing from 12 to 20 carbon atoms, sulphonated fatty acid amides and alkali metal salts of alkane sulphonic acids. Also present in the reaction mixture may be chain regulators such as hexyl, octyl, lauryl, dodecyl and myristyl mercaptans. The resulting graft polymers may be formed into dyeable films and fibres from solution in solvents such as dimethyl formamide, dimethyl acetamide, dimethyl cyanamide, dimethyl cyanoacetamide, dimethyl - beta - cyanopropionamide, dimethyl methoxyacetamide, ethylene carbonate, ethylene carbamate, gamma-butyrolactone, N-methyl-2-pyrrolidone, glycolonitrile, malononitrile, ethylene cyanhydrin, dimethyl sulphone, dimethyl sulphoxide, tetramethylene sulphone, tetramethylene sulphoxide, N-formylpyrrolidine, N-formylmorpholine and N:N1-tetramethylmethane-phosphonamide. Specifications 358,534, [Group IV], 715,194, 764,297 and 764,298 are referred to.