Role of Solvent in the Heterophase Copolymerization of Maleic Anhydride with Vinyl Isobutyl Ether

Abstract

Abstract The aim of our investigation was to find out to what extent benzene (B) could be replaced by less toxic solvents like toluene (T) and ethylbenzene (EtB) in an alternating heterophase copolymerization of maleic anhydride (MAn) with vinyl isobutyl ether (ViBE). Low yields excluded copolymers obtained by the use of EtB. The investigations were designed to establish relations between initiator (benzoyl peroxide) concentrations and such parameters as weight-average molecular weights ([Mbar] w), intrinsic viscosities ([η]), sedimentation constants (s 0), and degrees of conversion (α). By raising the initiator concentration in benzene from 0.00 to 0.20 mol% after 4 hours of polymerization at 60°C, an increase of [Mbar] w from 29 × 103 to 850 × 103 g/mol was found. Parallel to that, the degree of conversion went from 12% up to 98%. In toluene, on the other hand, the corresponding increase of [Mbar] w was from 80 × 103 to 290 × 103 g/mol only, whereas the degrees of conversion were 61% and 81%. The intrin...