GRAFT-COPOLYMERIZATION OF METHYL ACRYLATE BY CERIC ION IN THE PRESENCE OF A CONTROLLED AMOUNT OF OXYGEN

Methyl acrylate (MA) was grafted onto dissolving pulp by ceric sulfate in the presence of a controlled amount of oxygen. The magnitude and location of the maximum on the conversion vs the agitation speed curve are dependent on reaction conditions. The concentration of eerie sulfate and the reaction time are the most important determinants. The type of stirrer has only limited influence. The Ce(IV) consumption rises with increasing stirring speed due to higher diffusion of oxygen to active centers and is higher than for the oxidation of cellulose. The difference in Ce(IV) consumption for grafting and oxidation is not directly related to the amount of homopolymer because the grafting efficiency is independent of agitator speed. The rate of grafting is proportional to the amount of monomer to the second power, as a result of reaction of primary radicals with oxygen. Adding the MA later than the eerie sulfate causes a considerable increase in the induction period but no increase in the conversion. Hypothetical conversion curves are presented. © 1990, Taylor & Francis Group, LLC. All rights reserved.