Synthesis of POSS-diamine and its modification researches on polyimide materials

In this paper, γ-aminopropyltriethoxysilanes (APS) and penyltriethoxysilanes (PTES) were adopted to prepare bifunctionalized amino POSS, namely POSS-diamine, via hydrolytic co-condensation in ethanol/H₂O solvent under the catalysis of TEAOH. The structure of the product was characterized by FTIR, ¹H-NMR, ¹³C-NMR and ²⁹Si-NMR, which revealed that the structure of the product was ideal. POSS-diamine and ODA were used to react with PMDA to prepare POSS modified polyamic acid. After thermal imidization process, a series of polyimide hybrid films with different POSS-diamine content were obtained. The thermostability, mechanical properties and atomic oxygen corrosion resistance property of hybrid films were measured by TGA, tensile testing machine and plasma atomic oxygen producer. Results indicated that thermal property of these hybrid films was still excellent, while mechanical performance slightly decreased. The atomic oxygen resistance property was improved nearly four times when POSS-diamine addition reached 7(mol)%.