J. D. Memory

Electron spin resonance study of a cured epoxy resin exposed to high-energy radiation

Abstract Tetraglycidyl-4,4′-diaminodiphenyl methane cured with 4,4′-diaminodiphenyl sulphone was irradiated with varying dosages of 0.5 MeV electrons and 1.17 and 1.33 MeV gamma rays and was studied using electron spin resonance. The radical concentration increases with increasing radiation dose and decays, at ambient temperature, in a way consistent with a model that assumes two simultaneous second-order reactions occurring in different zones.

Radiation Effects on Graphite Fiber Reinforced Composites

The effects of radiation on graphite fiber reinforced composites, particularly those using an epoxy matrix, are reviewed. Specifically, it is concluded that there is no catastrophic deterioration of mechanical properties for doses up to thousands of Mrad, provided the irradiation occurs in an oxygen-free environment.

Effects of 0.5‐MeV electrons on the interlaminar shear and flexural strength properties of graphite fiber composites

Composite samples of graphite fibers in both an epoxy matrix and a polyimide matrix have been prepared with different fiber arrangements and irradiated with 0.5‐MeV electrons up to 104 Mrad. Interlaminar shear strengths decreases significantly with radiation dosage while little change was observed in the flexural strengths and moduli. The results indicate that radiation causes significant degradation at the interface but not much change in the fiber or matrix.