Radiochemical yields of graft polymerization reactions of cellulose

摘要

AbstractThe preparation of radiation‐induced graft polymers of cotton cellulose, while retaining the fibrous nature and high molecular weight of the cellulose, depended primarily on the radiochemical yields of cellulose reactions and of graft polymerization reactions. Yields of the initial major molecular changes in cellulosic polymer indicated that, in the case of scission of the molecule and carboxyl group formation, chain reactions were not initiated by radiation; however, in the case of carbonyl group formation chain reactions were initiated but quickly terminated. Generally, experimental procedures, used in graft polymerization reactions, were: (1) simultaneous irradiation reactions, that is, application of monomers or solutions of monomers to cellulose or chemically modified celluloses, then irradiation; and (2) post‐irradiation reactions, that is, irradiation of cellulose or chemically modified celluloses, then after removal from the field of radiation, contacting the irradiated cellulose with monomer. Some of the most important factors influencing the radiochemical yields of graft polymerization reactions of styrene and acrylonitrile onto cellulose were: concentration of monomer in treating solution; solvent; ratio of monomer solution to cellulose; prior chemical modification of cellulose; and absence of oxygen, particularly in post‐irradiation reactions. Experimental data were presented, and the direct and indirect effects of Co60γ‐radiation on these reactions were d