Swelling and gas evolution in irradiated organic matrix composites - A review

Abstract

When irradiated with high energy particles, all organic materials produce gas as a result of bond scission or nuclear displacement reactions that may occur and the rate of gas evolution can be related to the chemical structure of the material. The relationship between rate of gas evolution and temperature of irradiation is complex, but it is believed that providing the material is irradiated at a temperature below its Tg, there is little influence of temperature on the total gas evolved. A number of investigators have considered the possibility that radiolytic gases, if not lost by normal diffusion processes, will be trapped within the material and so causes the resin to 'swell'. There is a particular concern that when materials are irradiated at low temperatures, gases may be released suddenly as the material is warmed, minimising the possibility of loss by diffusion and so leading to an increase in dimensions. This paper reviews the literature on gas evolution and any associated swelling that may occur and for epoxies, correlates gas evolution rates with chemical structure. © 2010 American Institute of Physics.