| 摘要 |
Copolymers of vinyl acetate or acrylic or methacrylic esters with acrylamide or methacrylamide are cross-linked by adding thereto a polyisocyanate, e.g. toluylene isocyanate, or a polyaldehyde, e.g. glyoxal or trioxane, and heating the mixture at a temperature of from 25 DEG to 105 DEG C. In a modification of the process the amido groups of the copolymer are hydrolysed, e.g. with aqueous sulphuric acid, and the resulting carboxyl groups reacted with a polyalcohol, e.g. pentaerythritol, a polyamine or an inorganic polyvalent base. The examples describe the copolymerization of acrylamide with vinyl acetate or methyl acrylate in solution in toluene in the presence of benzoyl peroxide and the copolymerization of acrylamide with methyl acrylate in an aqueous medium containing sodium sulphoricinate, an oleic acid/ethylene oxide condensate and ammonium persulphate. |
