Polymer composition and method

The residual monomer content of an acrylamide polymer is reduced by forming an aqueous solution of the polymer and incorporating therein a sulphite in an amount of at least one mol. per mol. of acrylamide monomer in the solution. The polymer may be polyacrylamide or a copolymer of acrylamide with acrylic or methacrylic acid, methacrylamide, a vinylbenzyl-ammonium compound, vinylbenzene sulphonic acid, maleic acid, ethylene, butylene, styrene, an acrylate or methacrylate, vinyl chloride or vinylidene chloride. The amide groups of the polymer may be partially hydrolysed. The sulphite may be ammonium, magnesium or an alkali metal sulphite or bisulphite or calcium bisulphite, and may be added to the polymer solution in aqueous solution or may be formed in situ by introducing sulphur dioxide into the solution in gaseous form together with an equivalent amount of gaseous ammonia or aqueous alkali metal hydroxide solution.