In situ formation of POSS layer on the surface of polyimide film and anti-atomic oxygen of SiO2/POSS coatings

Polyhedral oligomeric silsesquioxane (POSS) nanoparticles have attracted wide attention due to their unique capability to reinforce polymers. However, if POSS cannot be uniformly dispersed in the polymer matrix, the desired properties of composites will be reduced. To solve this problem, a method of in situ formation of POSS layer on the surface of polyimide (Kapton) was explored, which not only kept the original properties of polymer unaffected, but also endowed the composites with new properties. The Kapton film completely wetted by γ-aminopropyltriethoxysilane (APTES) was placed in a solution containing tetraethylammonium hydroxide (TEAOH) catalyst, and a POSS layer was gradually grown on the Kapton surface. Subsequently, SiO2 coating was deposited on the surface of POSS layer by magnetron sputtering to prepare SiO2/POSS/Kapton (SPK) samples. FTIR and XPS analyses showed that a layer with POSS structure was formed on the surface of Kapton after 6 h self-growth. Atomic oxygen irradiation test shows that the erosion rate of 6 h SPK sample is 0.19 × 10−24 cm3/atom, only equivalent to 6.0 % of original Kapton, which improves the corrosion resistance of polymer materials.