Peroxo Salts as Initiators of Vinyl Polymerization IV. Polymerization of Acrylonitrile by the Peroxomonosulphate–Oxovanadium(IV) System

Abstract

A detailed kinetic study of the aqueous polymerization of acrylonitrile (AN) initiated by peroxomonosulphate (HSO5−, PMS)–oxovanadium(IV) redox system has been made in the temperature range 30°—60°C under dearated conditions at a constant ionic strength (μ=1.20). The effects of [monomer], [PMS], [oxovanadium(IV)], [H+], μ and temperature on rate of polymerization, Rp were investigated and the Rp was found to be proportional to [AN]1.5 [HSO5−]0.5 [oxovanadium(IV)]0.5. The kinetic and thermodynamic parameters were evaluated and are discussed. A suitable reaction scheme involving redox reaction of HSO5− and oxovanadium(IV) with mutual termination is proposed. The expression for degree of polymerization, Xn was obtained by molecular weight determination of the formed polymers. A comparison was also made with a similar redox system involving peroxodiphosphate.