| abstract |
1,177,512. Preparation of acrylamide copolymers. NALCO CHEMICAL CO. 29 March, 1967 [15 April, 1966], No. 14294/67. Heading C3P. [Also in Division D2] Terpolymers having a molecular weight of 5,000,000 or more are made from (a) acrylamide, (b) a polymerizable carboxylic acid such as maleic or fumaric (including maleic anhydride) and (c) a water-soluble or waterdispersible unsaturated compound containing a polar group. Examples are given of the copolymerization in water-toluene medium of acrylamide, maleic anhydride and sodium methacrylate in a redox system of potassium persulphate and sodium metabisulphite. A surface-active anti-sticking agent (sorbitan mono-oleate) is also present. A copolymer of acrylamide and dimethylaminoethyl methacrylate hydrochloride is also described, prepared by polymerization in water-toluene medium with tertiary butyl hydroperoxide and a petroleum sulphonate. The products are used as additives to paper pulp (see Division D2). |