GB775409A - Improvements in the polymerization of unsaturated organic compounds in aqueous suspension - Google Patents

Abstract

Polymerization of an unsaturated organic compound which is water-insoluble and liquid under the polymerization conditions is carried out in aqueous suspension in the presence of a water-soluble copolymer of N-vinylpyrrolidone-2 and a minor amount of an ester of an acrylic acid, such as methyl, ethyl or butyl acrylate, as suspending agent. The unsaturated organic compound may be methyl methacrylate, styrene or a substituted styrene, such as a nuclear-substituted mono- or di-methyl styrene, alphamethyl or meta-ethyl styrene or an alkoxy or chlorostyrene. The styrene or styrene derivative may be copolymerized with acrylonitrile, N-vinyl carbazole, vinylidene chloride or methyl methacrylate. The polymerization may be carried out in the presence of a catalyst such as benzoyl or ditertiary butyl peroxide or azo isobutyronitrile. Porous masses may be obtained by adding to the monomers easily volatile non-polymerizable organic liquids such as butane or pentane or their mixtures with hexane, cyclohexane or with hexane and cyclohexane, to obtain polymer granules containing the liquids in dispersion, which are then heated to a temperature above the boiling-point of the organic liquid and above the softening range of the polymer. Examples describe the production of copolymers of N-vinylpyrrolidone-2 and methyl acrylate or methacrylate in aqueous solution in the presence of azo-bis-isobutyric acid nitrile or hydrogen peroxide as catalyst.