PRODUCTION OF PARTIALLY HYDROLYZED POLYACRYLAMIDE POLYMER

摘要

PURPOSE:To produce the titled finely powdered polymer efficiently, by adjusting the pH of an aqueous solution of an acrylamide-based monomer mixture to a specified value and partially hydrolyzing the amide groups simultaneously with the polymerization of the monomer. CONSTITUTION:A caustic alkali (e.g., NaOH) and a polybasic acid (salt) (e.g., boric acid) are added to an aqueous solution containing 10-50wt% monomer mixture of 50-100wt% acrylamide and 50-0wt% water-soluble vinyl monomer copolymerizable therewith (e.g., acrylic acid) to adjust its pH to 8.5-10.0. This aqueous solution is emulsified in an organic solvent (e.g., toluene) containing a dispersant or an emulsifier (e.g., sorbitan monolaurate). The formed emulsion is subjected to reversed phase suspension or emulsion polymerization at a temperature of 40 deg.C to the b.p. of the organic solvent for 2-8hr in the presence of a polymerization initiator and at the same time to the partial hydrolysis of the amide groups. The product is spray-dried to obtain the titled polymer having a degree of polymerization =10,000, a degree of hydrolysis of amide groups =1mol% and an average particle diameter =200mum.