Hydrolysis of polyacrylonitrile fibers under pressure (15 atm.) at 180-185° C by water gave a copolymer of acrylamide

acrylimide and the ammonium salt of acrylic acid and their homopolymers. The ammonium salt of polyacrylie acid after being dried

was partially decomposed into polyacrylie acid and ammonia. The final product consists of polyacrylie acid

its ammonium salt

polyacrylamide and polyacrylimide in the ratio of ca 13:36:18:33.