METHOD FOR PRODUCTION OF HIGH MOLECULAR WEIGHT PARTIALLY HYDROLYZED POLYACRYLAMIDE Russian patent published in 1997 - IPC

FIELD: chemical technology. SUBSTANCE: desired polyacrylamide is prepared by polymerization of acrylamide, the process is carried out in concentrated aqueous solutions, initial temperature in buffer solutions being 20-50 C. Mixture of sodium tetraborate with sodium hydroxide (their molar ratio being 1: 3 respectively), or mixture of disodium orthophosphate with sodium hydroxide (their molar ratio being 1:1) or mixture of sodium carbonate (its concentration being 0.02-0.36 mol/l) with sodium hydroxide (its concentration being 0.04-0.54 mol/l) are used as said buffer solution having pH 12.0-12.4. Reaction mixture is heated at 60-75 C within 5 h in vacuum or in inert atmosphere, polymer is dried and ground to prepare powder having size 0.1-5 mm. EFFECT: improved efficiency of the method. 8 tbl