Optical and Thermal Properties of Polycarbonate/Kaolinite Composites

The study deals with thermal and optical properties of polycarbonate kaolinite composite investigated under effects of UV-radiation and temperature. Optical properties were studied as a function of UV-wavelength and photon energy and the optical results obtained are analyzed in terms of the absorption formula for noncrystalline materials. It was found that the measured optical energy gap for the polycarbonate is greater than the polycarbonate kaolinite composite. The width of the energy tails of the localized states was calculated. Adding kaolinite into polycarbonate matrix may cause the localized states of different color centers to overlap and extend in the mobility gap. This overlap may give an evidence for decreasing energy gap when adding kaolinite in the polymer matrix. It was founded that the thermal conductivity increases with increasing temperature, due to thermal activation of the phonons in the polycarbonate kaolinite composite. It was observed that the thermal conductivity is affected by the addition of kaolinite into polycarbonate polymer. The enhancement in the thermal conduction is mainly attributed to the heat transferred by lattice vibrations and electrons during thermal activation.