Electrical properties of oil shale/polystyrene composites

The dielectric and AC conductivity of oil shale/polystyrene composites were studied as a function of frequency, temperature, and oil shale concentration through impedance measurements. It was found that the AC conductivity and the dielectric constant increase by increasing the applied frequency, temperature, and oil shale content in the composites. The activation energy and relaxation time of the thermally electrical conduction were determined. The dielectric behavior of the prepared composites was mainly attributed to the dielectric properties of the oil shale filler. The observed increase in the AC conductivity was mainly produced from the carbon content and metallic impurities existing in the composites. Fitting of the measured AC-electrical quantities through some theoretical models was satisfactory.