MATHEMATICAL-MODELING OF STYRENE BUTYL ACRYLATE COPOLYMERIZATION

An experimental investigation of the kinetics of the bulk free radical copolymerization of styrene/butyl acrylate initiated with 2, 2′-azobisisobutyronitrile (AIBN) was conducted at 50°C using various initiator concentrations and initial monomer ratios including the azeotropic composition. The experiments were run through the full conversion range in order to collect composition, rate and molecular weight data. A mechanistic model for the bulk copolymerization of styrene/butyl acrylate was subsequently developed. The dynamic model can predict conversion, instantaneous and accumulated copolymer composition and number-average and weight-average molecular weights. Model predictions were compared with experimental data and were found to be in agreement. From this interplay of experimental and modelling efforts, more light was shed on the kinetic mechanisms of this important copolymer system. Postulations were made concerning branching characteristics and the significance of the penultimate versus terminal unit effects. © 1990.