Effect of clay on the dielectric relaxation of ethylene propylene rubber using thermally stimulated discharge current measurements

Abstract

Clay filler in EPR (ethylene propylene rubber) causes a peak in the TSDC (thermally stimulated discharge current) spectra at about 40 /spl deg/C. The peak displays dipole behavior and has an activation of 0.48eV. It seems to consist of one single relaxation peak and two smaller peaks which have not yet been analyzed. Reducing the clay concentration and particle size reduces the size of the peak. The polarization mechanism which causes this peak is not clear. It is possible that aggregation of the clay, adhesion of the clay to the polymer, or particle-particle interactions may affect this mechanism.<>