Amine-functionalized POSS cross-linked the poly(imide siloxane) block copolymers nanocomposites: preparation, thermal properties, against atomic oxygen erosion

Spacecrafts circling in low earth orbit suffer from highly reactive atomic oxygen (AO). To shield AO from erosion, a series of polyimide (PI) copolymer containing α,ω'-Aminopropyl poly(dimethyl siloxane)PDMS(Mn = 860 g mol−1), Octa(aminophenyl) silsesquioxanes (OAPS) were successful prepared by a two-step copolymerization. By controlling the amount of dianhydride, the different chain length block dianhydride capped poly (amic acid siloxane) (PAAS) was obtained. Then, the PAAS was reacted with OAPS which contains polyhedral oligomeric silsesquioxane (POSS) and surrounds eight amine groups to give the copolymers film with heat imidization. The effects of the different chain length block of the copolymers on the morphology and structure were investigated using field emission scanning electron microscopy (SEM) and FTIR, respectively. DSC, DMA, TGA and TMA were using to determine the thermal properties of the copolymer films. A poly(imide siloxane) copolymer with POSS nanocomposites show the best atomic oxygen (AO) resistance with the lowest erosion yield of 0.37 × 10−24 cm3 atoms−1. The results indicate that the copolymer films are capable of providing protection against atomic oxygen (AO) attack and may find wide usage in aerospace.