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

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 (Al2O3) was treated with a silane coupling agent of \(\boldsymbol{\gamma} \)-aminopropyltriethoxysilane (KH550), which introduces organic functional groups on the surface of Al2O3 nanoparticles. Then fluorinated polyimide (PI) was synthesized from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride and 4,4′-diaminodiphenylsulfone. Finally, PI/modified Al2O3 nanocomposite films having 3, 5, 7 and 10% of Al2O3 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 Al2O3 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.