Simulation of polymer film and surface behaviour in a space environment

The outer surfaces of space apparatus are subjected to the action of various factors of a space environment. For polymer materials at low earth orbits (altitudes 200–700 km) the sun's radiation and fast atomic oxygen from earth's residual atmosphere play the main role between these factors. We have shown that the solar radiation with wavelengths 177–220 nm plays the decisive role in deterioration of mechanical properties of polytetrafluoroethylene films. For films of polyimide of Kapton type the main destructive factor is the fast atomic oxygen (5 eV) which is responsible for erosion of this polymer. It was shown that fast atomic oxygen reacts with polyimide predominantly by a mechanism similar to the mechanism of thermal atomic oxygen reactions. The rather deep (more than 50 Å) penetration of atomic oxygen into polymer surfaces was observed.