Redox polymerisation, 6. Kinetics of the polymerisation of acrylonitrile initiated by the systems glycerol-Mn(III) and allyl alcohol-Mn(III) in aqueous sulfuric acid

Abstract

Polymerisation of acrylonitrile initiated by the redox systems glycerol-Mn(III) and allyl alcohol-Mn(III) is investigated in the temperature range 25-45°C in aqueous sulfuric acid/acetic acid and aqueous sulfuric acid, respectively. Oxidation of both glycerol and allyl alcohol proceeds through an intermediate complex. Decomposition of the complex is reversible with glycerol, whereas with allyl alcohol it is irreversible. Addition of Mn(II) retards both oxidation and polymerisation in the former system, while with the latter oxidation in the absence of monomer is unaffected, although polymerisation rates are retarded. Mutual termination predominates with the system glycerol-Mn(III), whereas primary radical termination accounts for the kinetics of polymerisation with the system Mn(III)-allyl alcohol. Rate and equilibrium parameters are evaluated and their significance is discussed.