Effects of Atomic Oxygen Irradiation on PDMS/POSS Hybrid Films in Low Earth Orbit Environment
In order to improve the atomic oxygen (AO) erosion resistance of polyimide films in low earth orbit space environment, a type PDMS/POSS hybrid coating on polyimide substrate was prepared based on a silanol terminated polydimethylsiloxane (PDMS-OH) and Octakis(trimethylsiloxy)octaprismosilsesquioxane (Q8[Si(CH3)3]8) by copolymerizing process in DMAc solution. The atomic oxygen exposure tests were carried out using a ground-based atomic oxygen simulation facility. The mass loss, surface morphology and surface chemical compositions of PDMS/POSS hybrid films before and after exposure to incremental AO flux were investigated by using microbalance and field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The data indicated that a silica-rich layer was formed on the surface of the hybrid coating when the coating is exposed to AO flux, which could provide a protective barrier on the surface preventing further degradation of the polymer during extended exposure to AO and obviously improved the AO resistance of polyimide films.
Zhong Cao, Xueqiang Cao, Lixian Sun, Yinghe He
M. M. Song et al., "Effects of Atomic Oxygen Irradiation on PDMS/POSS Hybrid Films in Low Earth Orbit Environment", Advanced Materials Research, Vols. 239-242, pp. 1368-1371, 2011