Abstract: The damage effects and mechanisms of proton irradiation with 50~200 keV energy to space-grade methyl silicone rubber was performed using a ground-based simulator for space irradiation environment. The changes in surface morphology, mechanical properties, cross-linking density, glass temperature, infrared attenuated total reflection spectrum, mass spectrum and pyrolysis gas chromatography-mass spectrum indicated that, under lower energy, the proton irradiation would induce cross-linking effect, resulting in an increase in tensile strengths and hardness of the methyl silicon rubber. However, after the irradiation of protons for more than 150 keV, the irradiation induced degradation, which decreased the tensile strengths and hardness, became a dominant effect. A macromolecular network destruction model for the silicone rubber radiated with the protons was proposed.

Key words: Methyl silicone rubber, Proton irradiation, Tensile strength, Infrared spectrum, Damage mechanism