Unusual free radical polymerization of vinyl acetate in anionic microemulsion media

The polymerization of vinyl acetate in one-phase o/w microemulsions stabili zed with Aerosol OT (AOT) is examined as a function of concentration and ty pe of initiator(V-50 and KPS) and temperature. Conversions and reaction rat es increase with increasing concentration of V-50 and temperature. Faster p olymerization rates and higher conversions are achieved with RPS because of the different electrostatic interactions between the charged microemulsion droplets and the free radicals of KPS and V-50. Average molar masses and p olydispersity indexes ((M) over bar(W)/(M) over bar(n)) are much smaller th an those observed in emulsion polymerization using the same surfactant, eve n at high conversions. Analysis of the molar mass distribution indicates th at chain-transfer reactions to monomer are the controlling chain-growth mec hanism in the polymerization of vinyl acetate in AOT microemulsions at all conversions.