BASE-HYDROLYZED STARCH-POLYACRYLONITRILE (S-PAN) GRAFT COPOLYMER . S-PAN-1-1, PAN MW 794000

Starch‐polyacrylonitrile (S‐PAN) graft copolymer consisting of one part starch and one part polyacrylonitrile (M. W. 794,000) was hydrolyzed with aqueous KOH at 80 and 100°C to polyelectrolytes containing carboxyl and amide functionality but void of infrared‐detectable amounts of nitrile. Viscosities of potassium salts of the polyelectrolytes in water were pH dependent with peak viscosities at 8.5. These dispersions were characterized by unusually high viscosities, 15,000 to 26,500 cp at 1% concentration, and by the ability to retain significant viscosities, 300 to 950 cp, upon dilution to 0.03% concentrations. A 1% dispersion of hydrolyzed S‐PAN had a viscosity of 5,000 cp in the presence of 8% KCl; however, the depressing effect of added salts on viscosity of aqueous dispersions of hydrolyzed S‐PAN increases as the valence of the cation increases. Copyright © 1969 John Wiley & Sons, Inc.