The Effect of Compressive Strain and Stress on Electrical Conductivity of Conductive Rubber Composites

Abstract

Abstract The electrical conductivity changes significantly when compressive strain and stress are applied on the conductive rubber composites derived from acrylonitrile—butadine rubber (NBR), ethylene—propylene—diene rubber (EPDM) and their 50:50 blend. The resistivity increases during application of compressive strain. However, the change of electrical resistivity depends on strain amplitude, amount of filler loading and type of polymer matrix. The change of resistivity with time for compressed samples has also been registered. But, during application of compressive stress (pressure), the resistivity is found to decrease for NBR and increase for EPDM and dual behavior is observed in blend. All the increase and decrease of resistivity with the application of stress and strain is explained on the basis of formation and destruction of a conductive network, which further depends on viscosity (stiffness) of the matrices. The observations are supported by the similar experiments with conductive silicone rubber composites.