Mechanism of Catalytic Polymerization of 2-Hydroxyethyl Methacrylate under the Influence of Vanadium(IV) Oxo Complex

An oxovanadium(IV) complex with dimethyl sulfoxide exhibits a substantial catalytic activity for the reaction of polymerization of 2-hydroxyethyl methacrylate (HEMA) with high selectivity for monomer. The complex does not catalyze polymerization of other monomers, including other methacrylates. A carbo-chain structure of polymeric HEMA is established by 13 C NMR. The resulting poly-HEMA has a narrow unimodal molecular mass distribution. It is found that the polymerization is catalytic in nature. A coordination mechanism for this polymerization is proposed.