Kinetics of polymerization of acrylonitrile initiated by the vanadium(V)-bisulphite redox system in sulphuric and perchloric acid media

The kinetics of polymerization of acrylonitrile, initiated by the free radicals formed in situ in the vanadium(V)-bisulphite redox system, was studied in aqueous sulphuric acid and perchloric acid media in the temperature range of 28–40 °C. The rate of polymerization was determined at various concentrations of the monomer and initiators. The effect of intermediate injection of catalyst was studied. The temperature dependence of the rate was studied and the activation parameters were computed. The resulting polymer (polyacrylonitrile (PAN)) was characterized by infrared (IR) and 1H NMR spectral analysis and by its molecular weight determined by the viscometric method. A possible mechanism consistent with the experimental data has been proposed.