Origin and Nature of the Activated Parameters in the Electrical Aging Equation

Abstract

We have shown elsewhere that the Eyring equation can describe the electrical aging of several polymers. This equation has two main activated parameters, namely the activated energy DeltaG and the activated volume DeltaV. In this paper, we confirm our previous supposition that DeltaG is related to the C-C bond strength by providing examples deduced from the electrical aging of polyethylene and polypropylene. We can now identify the origin and nature of the activated volume DeltaV for aging and breakdown of polymers. It is shown to be somehow associated with the concentration of broken bonds and on the maximum concentration of free charges in the aged sample. With the understanding of the physical sense of the two activated parameters, it is now possible to predict the life equation of simple insulating polymers from their basic physico-chemical properties. The significance of these calculations on the interpretation of other electrical properties is also briefly discussed.