| 摘要 |
1,153,207. Cationic carbamoyl polymers. DOW CHEMICAL CO. 18 Oct., 1966 [19 Oct., 1965], No. 46528/66. Heading C3P. Water-soluble cationic polymers are prepared by dispersing an aqueous solution of a watersoluble polymer composed of monoethylenically unsaturated monomer units, at least 20 mole per cent of which are units containing a carbamoyl group of the formula -CO-NH-R 1 (R 1 being H or C 1 -C 4 alkyl), in droplet form in a water-immiscible organic liquid, which is a non-solvent for the polymer, at 20-70‹ C. and then adding to the dispersion a watersoluble secondary amine and formaldehyde, or an adduct of these two compounds, so as to aminomethylate at least some of the amide groups of the polymer. The polymer product can be recovered by azeotropic distillation of the water present, and sedimentation or filtration to separate the polymer from the organic liquid; recovery can also be effected by extraction with a water-miscible solvent. The carbamoyl polymer may be derived from acrylamide, methacrylamide, N-methyl- or N-propyl-acrylamide, or an amide of maleic or fumaric acid; the amide component may be copolymerized with a monomer such as vinyl alcohol, alkali metal salts of acrylic or methacrylic acid, alkali metal styrene sulphonates, alkali metal maleates, N-vinyloxazolidinone, N-vinylpyrrolidone, 2-aminoethyl acrylate, trimethyl vinylbenzyl ammonium chloride, acrylonitrile, methacrylonitrile, ethyl acrylate, vinyl acetate, vinyl methyl ether and styrene. The amine reactant may be one having the formula R 2 -NH-R 3 where R 2 and R 3 are independently selected from C 1 -C 5 alkyl or hydroalkyl radicals (the total number of C atoms not exceeding 8) or R 2 and R 3 may together form a divalent hydrocarbon or oxahydrocarbon radical. The formaldehyde reactant may be used in the form of formalin, trioxymethylene or paraformaldehyde. Saturated aliphatic hydrocarbons and aromatic hydrocarbons are suitable as the water-immiscible organic liquid. Examples illustrate the aminomethylation of polyacrylamides which, in some cases, are stated to have a small proportion of the amide groups hydrolysed to carboxylate groups in the starting polymer. |
