SYNTHESIS AND IDENTIFICATION OF GRAFT-COPOLYMERS OF WOOD PULP AND 4-METHYL-2-OXY-3-OXOPENT-4-ENE

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 polymer ization coinitiated by calcium chloride, hydrogen peroxide on wood pul p in dimethylsulfoxide at 30 degrees C. The wood pulps used in this re search are unbleached products produced by chemical, thermal and mecha nical pulping. All of them contain 25 to 29 weight percent lignin. Sep aration of the grafted wood pulp from homopoly(1-methyl-1-(2-oxy-1-oxo propyl)ethylene) formed during the reaction was done by benzene extrac tion. The results show that after the reaction, virtually all the wood pulps have a weight increase and, for very high yield sodium bisulfit e pulp, a weight increase of up to 92.7% of the original weight of pul p was obtained. The Fourier transform infrared spectra of the benzene unextractable 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 poten tial use as a reinforcing material without use of coupling agents in m any hydrophobic polymer matrixes. The reaction products contain homopo ly(1-methyl-1-(2-oxy-1-oxopropyl)ethylene) and uniformly dispersed gra fted wood pulp. Under ordinary thermal compression conditions, thermop lastic composite objects can be made directly from the reaction produc ts which contain up to 56 weight percent wood pulp.