Effect of carbon blacks with various structures on electrical properties of filled ethylene-propylene-diene rubber

The effect of carbon blacks on the electrical properties of filled EPDM is investigated by comparing five types of carbon blacks. Electrical tests show that EPDM filled with carbon black having a large value of surface area (conductive carbon black, CCB) displays the low volume and surface resistivities, and easily succumbs to dielectric breakdown. EPDM/CCB composites show the lowest dielectric constant and highest dissipation factor. Hence, a CCB with large surface area and high content of sulphur on the surface is suitable for conductive polymers; whereas, EPDM filled with other carbon blacks is useful for insulation applications.