Effects of atomic oxygen irradiation on structural and tribological properties of polyimide/Al _2O _3 composites

摘要

To understand the effects of atomic oxygen (AO) irradiation on the structural and tribological behaviors of polymer composites, polyimide/Al _2O _3 composites were irradiated with AO in a ground-based simulation facility. The structural changes were characterized by X-ray photoelectron spectroscopy and attenuated total-reflection FTIR, whereas the tribological changes were evaluated by friction and wear tests as well as scanning electron microscopy analysis of the worn surfaces. It was found that AO irradiation induced the oxidation and degradation of polyimide molecular chains, which increased the O concentration and decreased the C concentration in the composite surfaces. The destruction action of AO changed the surface chemical structure and morphology of the samples. Friction and wear tests indicated that AO irradiation decreased the friction coefficient but increased the wear rate of both pure and Al _2O _3 filled polyimides. In terms of the tribological properties, appropriate content of Al _2O _3 might be favorable for the improvement of tribological properties in AO environment.