Dielectric and AC Electrical Conductivity of Polycarbonate Kaolinite Composites

The dielectric and AC conductivity of polycarbonate/kaolinite composites were studied using the impedance measurements technique. The study was carried out as a function of frequency in the range from 20 kHz to 1 MHz, temperature in the range from 20 degrees C to 100 degrees C and kaolinite concentrations 0, 5, 10, and 15 wt%. It was observed that the AC conductivity and dielectric constant are increased by increasing the kaolinite content in the composite. The calculated activation energy varied with the filler content, temperature, and applied frequency. The observed electrical results fit approximately the reported empirical equations concerning the AC conductivity and dielectric behavior of polymer composites. However, the results were explained on the basis of the interfacial (space charge) polarization, dipolar polarization, and decrease of the hindrance produced by the polymer matrix.