Polymerization of vinyl acetate under high pressure

High pressure radical polymerization of vinylacetate with and without solvents has been investigated in the range of 1–2000 kg/cm2. The pressure has the ability to interrupt an occurrence of branching in bulk polymerization and the overall chain length of polyvinylacetate increases with pressure. In solution polymerization, the magnitude of the activation volume of chain transfer to solvent is in following order: toluene > chlorobenzene > bromobenzene. In both cases, the overall rates of polymerizations and the molecular weights of polymers obtained increased with increasing pressure. The overall activation volumes of vinylacetate polymerization are −17.4 ml/mole without solvent and −12.0 ml/mole in benzene.