Solvent effects in the free radical copolymerization of vinyl acetate and methyl methacrylate

A study was made of the effects of five solvents on the compositions of copolymers of vinyl acetate (VA) and methyl methacrylate (MMA) produced by free radical polymerization from feeds rich in VA. The MMA content was reduced significantly by propanol, unaffected by benzene and ethyl acetate and increased by acetonitrile and acetone. The effects observed for propanol, acetonitrile and acetone all reached a maximum at a solvent to monomer molar ratio of about 7:1. Experiments showed that neither monomer physical aggregation nor monomer carbonyl polarization phenomena could explain completely the observed effects. A complete explanation probably requires several factors including some associated with polymer radical reactivity.