Effect Of Atomic Oxygen/Proton Irradiation On The Tribological Properties Of Polyimide Composite Films

Polyimides were prepared by casting(PI)film and PI composite film,the effect of preparation temperature on the mechanical properties of PI films and adhesion were investigated.The friction and wear properties of the PI films in vacuum environment were evaluated.By using space environment ground simulation equipment,study the space environment of atomic oxygen and proton irradiation on the surface structure of polyimide and polyimide composite films,the influence of chemical composition and tribological properti es,discussed two types of mechanism of radiation effects on materials,the main results obtained are as follows: 1.The effects of preparation temperature on the properties of PI films was studied.The results showed that the mechanical properties and adhesion of PI films improved obviously with the increase of the preparation temperature.However,the friction coefficient and wear rate of the PI films increased gradually with increasing the preparation temperature.The PI films prepared at 300 ? exhibited the best comprehensive performance.2.The effects of atomic oxygen Irradiation on PI and CNF/PI composite films were studied as well.Atomic oxygen irradiation induced the molecular chain rupture and degradation occuring the PI film surface.The element content and morphology of the film have been changed.The addition of carbon nanofibers in PI could enhance the friction and wear properties and atomic oxygen resistance.Friction coefficients of two kinds of thin film with the increase of atomic o xygen irradiation time increased.3.The effect of atomic oxygen Irradiation on PI and POSS/PI composite films were studied.The results are the PI molecular chain structure of the film surface was oxidized and degraded by the irradiation of atomic oxygen,and the POSS material was added to improve the anti atomic oxygen properties of the composite films.The effect of atomic oxygen irradiation on the tribological properties of PI composite films is different with the filling amount of POSS.The composite film with a filler content of 10% POSS has best anti atomic oxygen properties and friction and wear properties.4.The effects of proton irradiation on PI films was studied.This research discovered that the structure of PI molecular chain has been changed by the proton irradiation,Carbonization reaction occurred on the surface of PI film,Hardness and elastic modulus increased significantly,and the average roughness decreased.Proton irradiation improves the friction and wear properties of PI films.