Spectral Observation of Defects in Space-Use Polymer Chain Irradiated by Ultraviolet Light

Abstract

We discuss some effects of the optical damages to polymer, on the basis of infrared spectroscopic, electron spin resonance (ESR), and dynamic viscoelastic data analysis related to the study of the effect of the space medium in space. It is revealed that UV light from the sun has a strong influence on the surface of spacecraft, as does atomic oxygen. After the irradiation of space-use polymer in the laboratory for several days, which corresponds to more than two years of use in space, the spectral change was observed by using the attenuated total reflectance (ATR) method. The IR spectra due to CO2, C=O, and alphatic CH, groups ( n = 1–3) appeared to indicate that the surface of the polymer was oxidized. The viscoelastic spectra revealed a cut in the polyimide chain. The radical intermediates in the breakdown of the polymer were observed by means of ESR spectroscopy.