| 摘要 |
1,148,005. Ionic vinylamide polymers. AMERICAN CYANAMID CO. 22 June, 1966 [12 July, 1965], No. 27992/66. Heading C3P. [Also in Division D2] Ionic hydrophilic vinylamide polymers containing cationic or anionic units and -CHOHCHO substitutents attached to N atoms of the amide groups are prepared by reacting a parent ionic, hydrophilic, waterdispersible vinylamide polymer with sufficient glyoxal to form a thermosetting product, said parent vinylamide polymer having a molecular weight not greater than 100,000. (The term "vinylamide polymer" refers to polymers which, in the unglyoxalated state, contain the recurring grouping In a modification, a non-ionic vinylamide polymer is reacted with glyoxal and ionic groups are then introduced in situ into the polymer. The glyoxalated products may have molecular weights of up to 1 million. Reaction of the parent polymer with the glyoxal can be effected by heating in aqueous, neutral or slightly alkaline solution. Examples illustrate the following polymerization and glyoxalation reactions: (1) methacrylamide is copolymerized with 2-methyl-5-vinylpyridine in aqueous isopropanol using ammonium persulphate catalyst and the product is glyoxalated; (2) acrylamide is copolymerized with diallyl-dimethyl ammonium chloride as in (1) and then glyoxalated; (3) the process of (2) is repeated except that part of the acrylamide is replaced by acrylonitrile; (4) acrylamide is copolymerized with N,N-diallyl melamine in dioxane using benzoyl peroxide catalyst and the product is glyoxalated; (5) polyvinylamine is converted to polyvinylurea (containing some unreacted amine units) by reaction with potassium cyanate in an aqueous medium containing hydrochloric acid, and the product is glyoxalated; (6) the process of (1) is repeated except that the monomers used are acrylamide and acrylic acid; (7) polyacrylamide is partially reacted with glyoxal and then with sodium bisulphite at an acidic pH, the final product containing pendent -CONH 2 , -CONHCHOHCHO and CONHCHOHCHOHSO 3 M groups (M being H or Na); (8) polyacrylamide is reacted firstly with 3-(dimethylamino) propylamine in ethylene glycol (with evolution of ammonia) and then with glyoxal; (9) sodium vinyl sulphonate is copolymerized with acrylamide and acrylonitrile in acidic, aqueous medium using a potassium persulphate/Na 2 S 2 O 5 catalyst, and the product is glyoxalated; (10) acrylamide is copolymerized with p-(chloromethyl)-styrene in acetone using benzoyl peroxide catalyst, the product is reacted with trimethylamine in aqueous medium to convert the chloromethyl groups to quaternary ammonium chloride groups, and then the polymer is treated with glyoxal. The glyoxalated polymers are useful for improving the wet strength of paper. |
