Effect of Climatic and Radiation Ageing on Properties of Glass Fibre Reinforced Epoxy Laminates

The effect of radiation on the properties of glass fibre reinforced epoxies was investigated. Radiation treatment with a maximum dose of 30 MGy was performed for virgin samples and after 0.5, 1, 2, and 5 years of exposure in cold, moderate and warm damp climates. Evaluation of climatic and radiation resistance was by the change in bending strength, interlaminar shear strength, and Young's modulus. Dynamic mechanical analysis and linear dilatometry were employed to investigate the epoxy matrix during ageing. It has been established that radiation treatment of both virgin and climatically aged samples causes the destruction of the interfacial bond. The large increase in mechanical properties observed is explained by the competing effects of two processes. There is little indication of the occurrence of additional crosslinking of the epoxy binder during irradiation. It is shown that ageing in the reverse order (radiation treatment with subsequent exposure to the climate) is more severe, and intensifies the changes in the properties of the material.