Electroinitiated polymerisation of methyl methacrylate mediated by titanium(III)-hydroxylamine redox system: A kinetic study

Methyl methacrylate was polymerised in an aqueous sulphuric acid-methanol medium in a divided cell by an electrolytically generated mediator species titanium(III). Titanium(III)-hydroxylamine sulphate was used as the initiator redox system. The reaction was confined to the cathode compartment and was found to proceed via a free radical mechanism. Kinetics of polymerisation were investigated for different initial monomer concentrations, acid concentrations, electrical currents, dielectric constants of the solvent and electrode materials. Chain termination of the polymer was due to coupling of growing macroradicals, also a fraction of the termination took place by chain transfer mechanism involving the organic solvent molecules. A suitable mechanism for titanium(III)-hydroxylamine sulphate mediated indirect electropolymerisation of methyl methacrylate has been proposed. (C) 2000 Elsevier Science Ltd. All rights reserved.