Enhancement of Properties of Wood by Gamma-induced Graft Polymerization

Abstract

This thesis discusses: 1. The established conditions which favour graft copolymerization with cellulose, when styrene-impregnated red pine wood is exposed to gamma radiation from the nuclear reactor. 2. The formation of the graft co-polymer within the wood structure effects significant improvement in bending strength, dimensional stability and moisture and water absorption. The homopolymerized styrene was distinguished from the graft copolymer with cellulose, by means of prolonged extraction of the homopolymer with benzene. 3. The transient species responsible for the grafting reaction were revealed by electron spin resonance studies to be long-lived free radicals, ostensibly from the cellulose. 4. Preliminary examination of the monomeric acrylonitrile and methyl methacrylate indicate them to be less effective than styrene in the enhancement of physical properties by this process.