Effect of Different Types of Carbon Black on Electrical Properties of Polypropylene/Carbon Black Composites

The relationship between volume resistivity and carbon black content of polypropylene/carbon black composites for four different conductive carbon blacks was studied. The percolation thresholds were measured. Morphology of the composites with different carbon black content was studied with SEM. The structure and particle size of these carbon blacks were observed and analyzed by means of TEM. Their surface area was also measured. The results showed that the larger the surface area and the smaller the particle diameter of the carbon black, the lower the percolation threshold. Especially, the carbon black with a hollow structure possessed a significantly lower percolation threshold than those of other three.