Effect of chromium chloride on the mechanical and dielectric properties of EPDM rubber

Measurements of Young’s modulus, dielectric loss and a.c. conductivity have been carried out on EPDM rubber samples loaded with different concentrations of CrCl3 (0,2,4 and 6 phr). The values of Young’s modulus was found to be linearly dependent on the CrCl3 content. Variation of the dielectric loss with temperature showed that CrCl3 may act as plasticizer. However, at higher frequencies the dielectric loss was found to be independent of frequency and the rubber samples may behave as non-polar dielectric. Investigations of the a.c conductivity suggested that the conduction in these rubber samples can be described by small polaron tunneling. In addition, conductivity was found to increase with CrCl3 content.