Atomic Oxygen-Resistant Polyimide Composite Films Containing Nanocaged Polyhedral Oligomeric Silsesquioxane Components in Matrix and Fillers.

For the development of spacecraft with long-servicing life in low earth orbit (LEO), high-temperature resistant polymer films with long-term atomic oxygen (AO) resistant features are highly desired. The relatively poor AO resistance of standard polyimide (PI) films greatly limited their applications in LEO spacecraft. In this work, we successfully prepared a series of novel AO resistant PI composite films containing nanocaged polyhedral oligomeric silsesquioxane (POSS) components in both the PI matrix and the fillers.

Lewis acid promoted carbon-carbon double-bond formation via organozinc reagents and carbonyl compounds.

Using cheap and readily available AlCl(3) as Lewis acid, functionalized aldehydes react with organozinc reagents to give (E)-alkenes stereoselectively in high yields.