Sadeghipour, Hojjatolah, Rafiee, Zahra, Ashouri, Davoud, Ahmadi, Ali, Mousavian, Saman, and Hekmati, Arash
A series of heterocyclic polyimides (PIs) having triazole moieties in their main chain were successfully prepared by the polycondensation of 3,5-diamino-1,2,4-triazole with four dianhydrides (3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 1,2,4,5-benzenetetracarboxylic-1,2,4,5-dianhydride, 4,4′-(hexaflouroisopropylidene)diphthalic anhydride, and 1,4,5,8-naphthalenetetracarboxylic dianhydride) via the soluble poly(amic acid) (PAA) precursors. Different amounts of titania (TiO2) nanoparticles were incorporated into the PAA matrix and then thermally imidized to form PI/TiO2. The obtained PAAs exhibited high compatibility with the TiO2 nanoparticles, thereby resulting in highly transparent PI nanocomposite films. The resulting nanocomposites were characterized using Fourier transform infrared spectroscopy, powder X-ray diffraction, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). TEM results indicated that the nanoparticles were dispersed homogeneously in the PI matrix on nanoscale. TGA confirmed that the heat stability of the nanocomposites was improved in the presence of TiO2 nanoparticles. [ABSTRACT FROM PUBLISHER]