Tri-butylborane Initiated Graft-copolymerization of Methyl Methacrylate onto Silk

Abstract

The Graft-copolymerization of methyl methacrylate (MMA) onto silk by tri-butylborane (TBB) was investigated in aqueous medium. It was found that the polymerization of MMA was accelerated in the presence of silk and the graft copolymer was obtained, while no grafting occurred in the absence of water. With rising temperature the rate of polymerization increased and the efficiency of grafting decreased. Both the percentage of grafting and the molecular weight of the polymer increased with increasing amount of silk. And also the percentage of grafting and the efficiency of grafting were increased by the pretreatment of basic amino acids. Glycidyl methacrylate and 2-hydroxyethyl methacrylate were also grafted onto silk, while no grafting was observed with other vinyl monomers. Amino acid analysis of hydrolysis products and their electron microscopic observation were made on the graft copolymers. On the basis of these results, the mechanism of grafting is discussed.