The radiolysis of poly(4-vinylpyridine) quaternary salt ion exchange resins

The radiation chemical yields of gaseous products, especially molecular hydrogen (H2), have been determined in the radiolysis of different poly(4-vinylpyridine) quaternary salt ion exchange resins with up to about 30 wt% of absorbed water. Irradiations were performed with 5 MeV 4He ions to simulate α-particle radiolysis and with γ-rays for comparison. The resins were quaternary salts of chloride and nitrate that are commonly used as matrixes in anion exchange and in plutonium recovery processes. An increase in H2 yields with increasing water loading was observed for both types of ionizing radiation in all of the resins. The yield of H2 for the nitrate-form was lower than that for the chloride and the yield of H2 was lower when the pyridinium nitrogen atom is coordinated to a methyl group rather than to atomic hydrogen. Spectroscopic studies included UV/vis, IR, and Raman and suggested that all the resins exhibit a high radiolytic stability.