EFFECT OF THE WAY OF ADDITION OF THE REACTANTS IN THE GRAFT-COPOLYMERIZATION OF A VINYL-ACETATE METHYL ACRYLATE MIXTURE ONTO CELLULOSE

In order to graft a vinyl acetate–methyl acrylate mixture onto cellulose, an exploration of the way of addition of the reactants has been made. The influence of several factors on the grafting parameters was studied, i.e., the order of addition of the ceric ion initiator and the monomer mixture, the removal of the ceric ion solution after a cellulose‐ceric ion contact time, and the delayed addition along the polymerization period of the more reactive monomer (methyl acrylate) towards the cellulosic radicals. Some grafting parameters were determined: grafting yield, grafting efficiency, cellulose conversion, molecular weight, ceric ion consumption, grafting frequency, number of grafted chains, and synthetic copolymer composition. After a short period (ca. 15 min) for the ceric adsorption on cellulose, a fast formation of cellulosic radicals arises in the initial stages of the polymerization. These initial cellulosic radicals should be trapped by a sufficiently reactive monomer if high grafting yield and high number of grafted chains are to be reached. A portion of the synthetic polymer chains anchored to cellulose that are formed in the first stages of the polymerization, which are generated from cellulosic hemiacetal groups, should constitute block copolymer. Copyright © 1990 John Wiley & Sons, Inc.