Aqueous polymerization of acrylonitrile initiated by the bromate–thiourea redox system

Abstract

Abstract The aqueous polymerization of acrylonitrile initiated by an acidified bromate–thiourea redox system has been studied under nitrogen atmosphere. The rate of polymerization is independent of thiourea concentration over the range 2–9 × 10 −3 M and reaches maximum at 9 × 10 −3 M . The rate varies linearly with [monomer]. The initial rate of polymerization as well as the maximum conversion increases within the range of 4–22.5 × 10 −3 M KBrO 3 , but beyond 22.5 × 10 −3 M the rate of polymerization decreases. The initial rate and the limiting conversion increases with increasing polymerization temperature in the range 30–45°C; and beyond 45°C they decrease. The effect of certain neutral salts, water‐soluble solvents, and micelles of cationic, anionic, and nonionic surfactants on the rate of polymerization has been investigated.