Effects of 170 keV proton and electron combined irradiation upon behaviors of thermosetting shape memory epoxy resin

Abstract

The effects of 170 keV proton and electron combined irradiation on shape memory epoxy resin (SMEP) under vacuum were investigated using complementary analytical techniques. It's showed that the shape recovery ratio of SEMP decreased with increasing the fluences. It was detected at least three kinds of free radicals in SEMP using electron paramagnetic resonance spectroscopy, including the nitrogen-containing free radicals and phenoxy-type ones. Those would be introduced from debonding of C–N and C–O groups due to the irradiation effects, which could be verified by the results of the X-ray photoelectron spectroscopy (XPS) spectra. The results of infrared spectroscopy further showed that the chain degradation induced by combined irradiation took place at the ether and methylene groups, respectively. Compared these results with the single-particle irradiation cases of either 170 keV electrons or 170 keV protons, it can be concluded that the debonding of the C–N and C–O groups at the branch-chain conjunction induced by electron irradiation and the chain scissions at the C–O and C–C groups within the main chains induced by proton irradiation were responsible for the degeneration of the shape recovery ratio. It was also found weak crosslinking between oxirane groups and hydroxyl groups during the combined irradiation.