Radiation yield of hydrogen chloride in gamma-irradiated poly(vinyl chloride) stabilized by epoxy compounds

The G_HCI values of γ-irradiated PVC mixtures were studied after addition of various amounts of three epoxy stabilizers: diglycidyl ether of 2,2-bis(4-hydroxy-3-methylphenyl)propane (I); diglycidyl ether of 1,1-bis(4-hydroxyphenyl)cyclohexane (II), and butyl-cis-9,10-epoxystearate (III). The results indicated that two processes are essential for the stabilization: HCI capture by the epoxy groups, and an external protective effect, due to the remaining part of the stabilizer molecule. The role of the benzene rings in stabilizers I and II, as compared with the protective effect due to the long chains of stabilizer III, is not as dominant as one would expect.