Effect of valence state of vanadium on stereoblock polymerization of methyl methacrylate with VOCl₃–AlEt₂Br catalyst system

Abstract

The polymerization of methyl methacrylate with the VOCL3–ALEt2Br catalyst system in n‐hexane has been studied. The first‐order dependence of rate of polymerization on catalyst and monomer concentrations, activation energy of 6.67 kcal/mole, and NMR spectra of polymer lend support to a coordinate anionic mechanism of polymerization. It has been shown that the vanadium in V+2 oxidation state is less active than V+3 oxidation state of active complex.