Abstract
PVA/TiO2/polypyrrole composites showing high dielectric constant have been synthesized by in-situ polymerization of pyrrole in an aqueous dispersion of 5% TiO2 and, 1 wt%, 3 wt% and 5wt% PVA. The structural, chemical and thermal properties of the composites were investigated by X-ray diffractometer, Fourier transform infrared spectroscopy and thermal gravimetric analysis, respectively. The structural morphology of the prepared samples was probed using the images obtained from scanning electron microscopy. An impedance analyzer was utilized to discuss the dielectric parameters. The data obtained from diffractometer confirmed the semi crystalline nature and the thermal gravimetric analysis confirmed the thermal stability of the prepared composites in a wide temperature range. The dielectric constant of 5 wt% PVA increased with filler contents up to 3.2 x 10(3) at 1 kHz and then decreased to 354 at 1MHz. in this way, an increase in dielectric constant of 5 wt% TiO2/ppy by 70 has been achieved.