Radical polymerization of di-n-butyl itaconate in the presence of Lewis acids

Intramolecular chain-transfer reaction takes place in polymerizations of itaconates at high temperatures and/or at low monomer concentrations. Polymerizations of di-n-butyl itaconate (DBI) were carried out at 60 °C in the presence of Lewis acids such as scandium trifluoromethansulfonate. Lewis acids hardly influenced the intramolecular chain-transfer reaction in bulk polymerizations. Polymerizations in methanol accompanied transesterification reaction catalyzed by Lewis acids. In polymerizations in toluene, catalytic amounts of Lewis acids were found to be effective in suppressing the intramolecular chain-transfer reaction. Lewis acids showed no significant influences on stereospecificity of polymerization, though isotactic-specificity increase in polymerizations of other acrylate monomers such as methyl methacrylate.