Radiation-chemical reactions of hydroaromatic compounds

Radiation-chemical reactions of 9,10-dihydrophenanthrene in cyclohexane solution and tetralin in 3-methylpentane matrix were studied by means of the pulse radiolysis at room temperature and by gamma-irradiation at 77 K, respectively, in order to elucidate chemically the inhibition of radiation-induced deterioration of polyolefins due to added hydroaromatic compounds. Observed optical absorption spectra showed that salute compounds efficiently scavenge positive hole and electron to form cation- and anion-radical. Two kinds of neutral radicals (by elimination of H-atom from, and by addition of H-atom to hydroaromatic solutes) were generated secondarily from the ion radicals. No evidence could be obtained for direct scavenging of H atom or solvent radicals by added solutes. The inhibition of radiation-induced deterioration of polyolefins is likely due to positive- and negative-charge scavenging rather than free-radical scavenging. (C) 1999 Elsevier Science B.V. All rights reserved.