Journal of Applied Polymer Science, Vol.84, No.5, 983-992, 2002
Electrochemical synthesis of poly[2-hydroxyethylmethacrylate] hydrogel: Kinetics and mechanism
2-Hydroxyethylmethacylate (HEM) was polymerized in an aqueous sulfuric acid-N,-dimethylformamide (DMF) medium in a divided cell by an electrolytically generated mediator species titanium(III). Titanium(III)-hydroxylamine sulfate 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 polymerization were investigated for variation in initial monomer concentrations, acid concentrations, electrical currents, dielectric constants of the solvent medium, and electrode materials. Chain termination of the polymer was due to coupling of growing macroradicals; also, a fraction of the termination took place by a chain transfer mechanism involving the organic solvent molecules. A suitable mechanism for titanium(III)-hydroxylamine sulfate mediated indirect electropolymerization of HEMA has been proposed.
Keywords:electroinitiated polymerization;poly(2-hydroxy ethylmethacrylate) hydrogel;kinetics and mechanism