Synthesis and properties of covalently bonded layered silicates/polyimide (BTDA-ODA) nanocomposites

Covalently bonded layered silicates/polyimide (BTDA-ODA) nanocomposites have been synthesized from gamma-(aminopropyl)triethoxysilane (APTS) grafted kenyaite and poly(amic acid). The existence of covalent bonds between APTS and silicates and between APTS and the dianhydride end groups of the polymer have been confirmed by solid-state C-13 and Si-29 nuclear magnetic resonance and infrared spectroscopy, respectively. The thermal, mechanical, and moistureabsorption retardation properties of these nanocomposites were found to improve substantially over those of neat BTDA-ODA. In particular, a maximum increase of 36 degreesC in the degradation temperature and a maximum reduction of 54% in moisture absorption are displayed by these nanocomposites.