Study of different degradation effects in UV-sensitive polymers using xenon lamp and deuterium lamp to simulate UV irradiation in space environment

This paper describes a study of the degradation effect of vacuum-UV radiation and near-UV radiation on polymeric materials in space by using vacuum-UV and near-UV simulators. To study the degradation of polymeric material due to UV irradiation, we used four UV-sensitive polymers and investigated their UV degradation mechanism. The polymers were polyamide (PA), polycarbonate (PC), polyvinyl chloride (PVC), and polyphenylsulfone (PPSU). We carried out a vacuum-UV irradiation test (UV wavelength 120 nm to 200 nm) by using a deuterium lamp and a near-UV irradiation test (UV wavelength 200 nm to 400 nm) by using a xenon lamp. Both UV degradation tests were conducted for 250 equivalents to sun hours in Space. To identify details in material degradation mechanisms, we examined the degradation of the polymer films by thermal optical properties and chemical structure changes using UV–visible spectroscopy, and X-ray photoelectron spectroscopy. The effects of the UV irradiation tests are compared and discussed in terms of thermal-optical properties and chemical changes.