Degradation Mechanism of Polyimide Film Irradiated by Gamma Rays

Abstract

The Co-60 radiation ground simulation test was conducted on the Mechanical property of polyimide film, thermo gravimetric and XPS was used to analyze the evolution mechanism of polyimide film in different dosages. It was found that the mechanical properties such as tensile force, tensile strength and rupture elongation of polyimide film in gamma ray radiation increase firstly and then exponent decrease. The corresponding initial decomposition temperature of the gamma ray-radiated polyimide film changed from 570°C to 590°C for weight-loss ratio of 2%. From XPS analysis, it can be found that there were rupture and crosslink of chemical bond in polyimide film. In early stage of gamma ray radiation, the rupture of C-N bond and following crosslink is for the increase of mechanical properties of polyimide film, and as the increase of radiation, the rupture of C=O and -N(CO) bond, formation of C-N bond, release of N was for the decrease of mechanical properties of polyimide films.