E.S.R. Study of the Reaction of Gases With the Free Radicals Produced by U.V. Radiation on the Surfaces of Acrylamide and Some Crystalline Materials. II. Results of H sub 2 , SO sub 2 and Cl sub 2 Admission to Acrylamide, Propionamide, Methacrylamide and Polyacrylamide

The differences in reactivity of various gases such as hydrogen, chlorine and sulphur dioxide with the radicals of irradiated acrylamide, propionamide and methacrylamide monomers and polyacrylamide were studied. The free radicals produced in acrylamide as well as in polyacrylamide were not affected significantly by the addition of hydrogen and sulphur dioxide. These gases diffuse through the interface between the monomer and polymer phases rather than reacting with the radicals produced in the locations where crystalline structure is defective. Gas chromatographic analysis of irradiation products indicates that the mechanism proceeds on a radical produced by hydrogen atom scavenging. The hydrogen atoms result only from radiolysis. Chlorine gas was found to be an agent for slowing down the radical decay rather than becoming a radical initiator. Consequently, irradiation in the presence of chlorine gas results in higher polymerization yields. 26 ref.--AA