Graft polymerization of acrylamide onto paper preirradiated with high energy electrons

The graft polymerization of acrylamide onto filter paper preirradiated in air with electrons from a 200-keV accelerator has been shown to lead to weight increases of up to 210%. The degree of grafting depends on the radiation dose, the moisture content of the paper, and the time interval between irradiation and grafting, but is independent of the radiation dose rate. The degree of grafting increases with the monomer concentration of the reaction medium, and increases as the grafting temperature is reduced. Irradiations in the presence of O2 or N2 and the effect of ferrous ions in the grafting solution indicated that peroxides derived from cellulose do not contribute significantly to the initiation reactions up to 60°C. The results are consistent with the degree of grafting depending primarily on the concentration of trapped radicals present in the paper at the time of copolymerization. The cellulose in the grafted material was degraded and the grafted acrylamide was isolated and its molecular weight measured and compared with a calculated value. The moisture regain characteristics of the grafted material are reported.