Studies on the Atom Transfer Radical Branching Copolymerization of Styrene and Acrylonitrile with Divinyl Benzene as the Branching Agent

The branching copolymerization of styrene and acrylonitrile with divinyl benzene as the branching agent was carried out using atom transfer radical polymerization. Nuclear magnetic resonance and triple detection size exclusion chromatography were used to analyze the reaction. The results suggest that the coupling reaction mainly takes place between the primary chains, forming slightly branched chains in the early stages. The coupling reaction between the branched chains becomes significant at the middle stages, forming highly branched chains. The reaction system consists of primary chains, slightly branched chains containing two primary chains and highly branched chains comprised of more than three primary chains. The weight fraction of the branched chains increases expectedly with monomer conversion.