Surface modified Al 2 O 3 in fluorinated polyimide/Al 2 O 3 nanocomposites: Synthesis and characterization

Abstract

Organic–inorganic hybrid materials consisting of inorganic materials and organic polymers are a new class of materials, which have received much attention in recent years. In the present investigation, at first, the surface of nano-alumina (Al 2 O 3 ) was treated with a silane coupling agent of $\boldsymbol{\gamma} $ -aminopropyltriethoxysilane (KH550), which introduces organic functional groups on the surface of Al 2 O 3 nanoparticles. Then fluorinated polyimide (PI) was synthesized from 4,4 ′ -(hexafluoroisopropylidene) diphthalic anhydride and 4,4 ′ -diaminodiphenylsulfone. Finally, PI/modified Al 2 O 3 nanocomposite films having 3, 5, 7 and 10% of Al 2 O 3 were successfully prepared by an in situ polymerization reaction through thermal imidization. The obtained nanocomposites were characterized by fourier transform infrared spectroscopy, thermogravimetry analysis, X-ray powder diffraction, UV-Vis spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. The results show that the Al 2 O 3 nanoparticles were dispersed homogeneously in PI matrix. According to thermogravimetry analysis results, the addition of these nanoparticles improved thermal stability of the obtained hybrid materials.