Synthesis and Identification of Graft Copolymers of Wood Pulp and 4-Methyl-2-oxy-3-oxopent-4-ene

Abstract

A set of graft copolymers of wood pulp and 4-methyl-2-oxy-3-oxopent-4-ene has been synthesized. The graft reaction is a free radical polymerization coinitiated by calcium chloride, hydrogen peroxide on wood pulp in dimethylsulfoxide at 30°C. The wood pulps used in this research are unbleached products produced by chemical, thermal and mechanical pulping. All of them contain 25 to 29 weight percent lignin. Separation of the grafted wood pulp from homopoly(1-methyl-1-(2-oxy-1-oxopropyl)ethylene) formed during the reaction was done by benzene extraction. The results show that after the reaction, virtually all the wood pulps have a weight increase and, for very high yield sodium bisulfite pulp, a weight increase of up to 92.7% of the original weight of pulp was obtained. The Fourier transform infrared spectra of the benzene unextr-actable fractions provide strong proof of grafting.

The grafted wood pulp is a surface-modified pulp. Grafting has changed the surface properties of the starting wood pulp from hydrophilic to hydrophobic. The importance of this change is that the grafted wood pulp has potential use as a reinforcing material without use of coupling agents in many hydrophobic polymer matrixes.

The reaction products contain homopoly(1-methyl-1-(2-oxy-1-oxopropyl)ethylene) and uniformly dispersed grafted wood pulp. Under ordinary thermal compression conditions, thermoplastic composite objects can be made directly from the reaction products which contain up to 56 weight percent wood pulp.