Investigation of the electrical properties of carbon black ethylene-propylene-diene (EPDM) natural rubber (NR) mixtures

Polymers have been used as electrically insulating materials for many years. Upon understanding that polymers can have conductive character, scientific studies have accelerated. The term conductivity in polymers refers to two different mechanisms. The first group of polymers itself is an insulator, and the conductivity property is added by mixing carbon black, metal fibers, short graphite fibers, metal coated glass fibers. In this model, the change of the resistance value of the filling material (%) in the composite with the volumetric ratio is examined. The second group of polymers have a self-conducting character due to their conjugated double bonds. In this study, 40 PHR (parts per hundred of rubber) and 50 PHR of carbon black were mixed into an insulating elastomer with different ratios of EPDM/NR mixtures and conductive elastomer composite was obtained. The resistances of the prepared samples were measured under free pressures under different pressures and the conductivity, resistivity and conductivity values were calculated and compared. Good results have been achieved despite phase mismatch in EPDM and NR mixtures. The additive ratio in the 40 PHR and 50 PHR composites affected conductivity. The ratio of fillers in 40 PHR and 50 PHR composites and the applied pressure have increased conductivity.