Graft copolymers of starch and poly(2‐hydroxy‐3‐methacryloyloxypropyltrimethyl‐ammonium chloride). Preparation and testing as flocculating agents

The title monomer (I) has been graft polymerized onto whole wheat starch with both ceric ammonium nitrate and ferrous ammonium sulfate–hydrogen peroxide initiation. Three graft copolymers, which contained 4.5, 12.1, and 15.2% grafted poly(I), were characterized as to molecular weight of grafted branches and grafting frequency. Graft polymerization was proved by fractional precipitation. Graft copolymers were tested as flocculating agents for diatomaceous silica and nonmagnetic iron ore. The graft copolymers with 12.1 and 15.2% grafted poly(I) compared favorably in flocculating ability with a commercial high molecular weight cationic polyacrylamide.