Degradation of mechanical properties of spacecraft polyimide film exposed to radiation environments

Abstract

Polyimide films are widely used in spacecraft, but their mechanical properties would degrade in radiation environments that include electrons, protons, atomic oxygen, near ultraviolet or far ultraviolet, etc. Implications of using polyimide films in spacecraft are reviewed in this paper. The degradation of mechanical properties of Kapton film exposed to electrons and far ultraviolet radiation environments were studied. It is known that the tensile strength and the rupture elongation of Kapton film decrease with the increase of the tensile deformation rate and the electron and far ultraviolet radiation. The far ultraviolet radiation will cause the rupture and cross linkage of molecular bonds in the film, deoxidation of C-CO, denitrification of C-N. The increase of C-H percentage is attributed mainly to the mechanical property degradation of Kapton film under far ultraviolet irradiation.