Characterization And Properties Of The Prepared Polyimide/Inorganic Nanocomposite Films

With the rapid development of modern science and technology, the traditionalpolyimide/inorganic composites have not met the needs of many fields. Due to thecomprehensive performance of well-dispersed polyimide/inorganic nanocompositesis good, the polyimide/inorganic nanocomposites become the hotspot research invarious fields.The chemical cross-linking polyimid/silica (PI/SiO2) nanocomposite films andpolyimide/titania (PI/TiO2) nanocomposite films were prepared through the sol-gelprocessing in this paper. The structures, morphologies and properties ofnanocomposite films were studied.Based on tetraethoxysilane (TEOS) as precursor, a series of un-bonded andbonded PI/SiO2hybrid films with different SiO2content were prepared via sol-gelmethod. The chemical and micro structures of nanocomposit films were investigatedby means of FT-IR and SEM. The thermal and mechanical properties of films weretested by TGA and electronic universal testing machine. The results showed that thesilica nanoparticles well dispersed in the PI matrix, and the sizes of the particles in PImatrix were about20-30nm. The thermal stability of hybrid films was higher thanpure PI, and the tensile strength improved obviously. The maximum of bonded andun-bonded films are105.4MPa and87.3MPa, when the concentrations are10wt%and8wt%.Put the tetrabutyl orthotitanate (TBOT) as precursor, a series of bonded PI/TiO2hybrid films with different TiO2content were prepared via sol-gel processing. Thechemical and micro structures of nanocomposit films were investigated by means ofFT-IR, XRD and SEM. The dielectric properties and corona-resistant characteristicwere investigated by dielectric spectrum and corona-resistant apparatus of highfrequency pulse voltage tester. The results indicated that the chemical interaction between the two phases resulted in the formation of well-dispersed nanoparticles(30-40nm) in the PI matrix, the dielectric constant was higher than pure PI, and thecorona-resistant characteristic improved markedly. When the concentration ofnano-TiO2was4wt%, the corona-resistant life was119min.