The retarded-photoelastic effect in γ-irradiated crosslinked polyesters was investigated at characteristic temperatures by the apparatus used in our previous works. The results obtained are following. (1) The R. P. E. transition temperature was shifted to the higher temperature with the dosage of γ-rays, and in some cases (in the vicinity of the R. P. E. transition temperature), a reversal in sign of the retarded-photoelastic coefficient was observed from positive to negative. (2) Above the glass transition temperature, the motion of the phenyl group of the side chain is not almost hindered sterically, even if the samples are irradiated by the γ-rays. In the temperature range, the retarded-photoelastic coefficient is, therefore, hardly affected by radiation dose. (3) The retarded-photoelastic effect in irradiated crosslinked polyesters can be explained as the summation of two contributions… a positive contribution from phenyl groups in the backbone chain oriented parallel to the backbone plane, and a negative contribution from phenyl groups of the side chain oriented perpendicular to the backbone chain.
抄録全体を表示