文献类型：期刊文献

英文题名：Resistance of POSS Polyimide Blends to Hyperthermal Atomic Oxygen Attack

作者：Qian, Min[1,2];Murray, Vanessa J.[1];Wei, Wei[1];Marshall, Brooks C.[1];Minton, Timothy K.[1]

机构：[1]Montana State Univ, Dept Chem & Biochem, 103 Chem & Biochem Bldg, Bozeman, MT 59717 USA;[2]East China Univ Sci & Technol, Dept Phys, Shanghai 200237, Peoples R China

年份：2016

卷号：8

期号：49

起止页码：33982

外文期刊名：ACS APPLIED MATERIALS & INTERFACES

收录：;EI(收录号：20165103152282);WOS:【SCI-EXPANDED(收录号:WOS:000389963300072)】；

基金：This work has been supported by the U.S. National Science Foundation (NSF-CHE-1266032). V.J.M. is grateful for support awarded by DoD, Air Force Office of Scientific Research, National Defense Science, and Engineering Graduate (NDSEG) Fellowship, 32 (Code of Federal Regulations) CFR 168a. SEM, XPS, and AFM data were collected at the Image and Chemical Analysis Laboratory (ICAL) at Montana State University, and AFM images were collected by Laura Kellerman of ICAL.

语种：英文

外文关键词：atomic oxygen; polyimide; POSS; polyhedral oligomeric silsesquioxane; low Earth orbit; hyperthermal

摘要：Copolymers of polyhedral oligomeric silsesquioxane (POSS) and polyimide (PI) have shown remarkable resistance to atomic oxygen (AO) attack and have been proposed as replacements for Kapton on the external surfaces of spacecraft in the harsh oxidizing environment of low Earth orbit (LEO). POSS PI blends would be an economical alternative to the copolymers if they also resisted AO attack. Thus, blends of trisilanolphenyl (TSP) POSS and PI with different weight percentages of the Si7O9 POSS cage were cast into films and exposed to a hyperthermal AO beam, and they were characterized in terms of their recession, mass loss, surface morphology, and surface chemistry. In order to compare the AO resistance of the blends with POSS PI copolymers, samples of previously studied copolymers were also investigated in parallel with the blends. For all POSS PI materials, the AO resistance increased with increasing AO fluence and with increasing POSS cage loading. At similar POSS cage loadings and exposure conditions, the TSP POSS PI blends showed comparable erosion yields to the POSS PI copolymers, with specific samples of blends and copolymers achieving erosion yields as low as 0.066 X 10(-24) cm(3) atom(-1) with an AO fluence of 5.93 X 10(20) O atoms cm(-2). SEM and XPS analyses indicated that passivating SiOx layers were formed on the surfaces of all POSS-containing polymers during AO exposure. Thus, a TSP POSS PI blend is proposed as a low-cost variant of a POSS polyimide for use in extreme oxidizing environments, such as LEO.