Effects of Ionizing Radiation on Polyvinyl Alcohol II. Changes of Physical Properties of the Irradiated Specimen Caused by Heat Treatment

Abstract

The physical Properties of polyvinyl alcohol irradiated by deuterons or gamma rays were found to change remarkably by heat treatment. Irradiation causes the decrease of the molecular weight and the increase of the carbonyl groups. When these specimens are heated above 120°C, however, the solubility diminishes considerably and even gel formation occurs for highly irradiated ones. Infrared absorption spectra revealed that the number of carbonyl groups formed by the irradiation decreased greatly as a result of heat treatment. Some discussion are given on the process of gel formation.