The effect of cable oil diffusion on the electrical conductivity of EPDM compounds

This work examines the effects of diffusing cable oil on the electrical behavior of elastomeric compounds based on EPDM, as used in semiconductive elements in accessories for application on paper-insulated lead-covered (PILC) cables. The behavior of volume resistivity is monitored as a function of the amount of cable oil diffused into the material. Resistivities up to the typical insulator range (similar to 10(13) Ohm-cm) are observed as a consequence of swelling due to the presence of the diffused oil. The measured volume resistivities of the oil-impregnated compound are then compared to predictions from the theory of electron transport in conductor-filled polymers.