Polymerization of acrylonitrile initiated by thiourea–chromium(VI) redox system

Abstract

The kinetics of polymerization of acrylonitrile initiated by Cr(VI)–thiourea and Cr(VI)–ethylene thiourea have been studied at 35, 40, and 45°C in nitrogen. The rates of polymerization and of disappearance of Cr(VI) were measured. Chromic acid alone did not initiate the polymerization under deaerated and undeaerated conditions. On the basis of the experimental observation of the dependence of the rate of polymerization R_p, the rate of Cr(VI) disappearance, –R_m, etc., on various variables, a suitable kinetic scheme was proposed and various rate and energy parameters were evaluated.