Study on electrical properties of activated carbon black filled polypropylene composites using Impedance analyzer

Carbon black was activated and then filled into polypropylene to prepare conductive composites, of which the electrical properties, including impedance Z, phase angel theta and dissipation factor tg delta, as a function of frequency and carbon black concentration were investigated using impedance analyzer. The percolation threshold of 5wt% carbon black concentration was obtained. It was found that the variation of AC electrical properties as a function of frequency is dramatic and dependent on the carbon black concentration. It was also found that dependence of the real part and the imaginary part of impedance on frequency decreases with the increased concentration of carbon black, while that of phase angle and dissipation factor increases. Based on the corresponding results, the conductive network model and the corresponding equivalent circuit were constructed.