Temperature-time dependence of the electric strength of polymers and the effect of some factors influencing this dependence

Abstract The temperature-time dependence of the electric strength of polycaprolactam and PVC films has been investigated as well as the influence of electrical discharges and of orientational stretching on the latter dependence. The results obtained show that the activation energy of electrical fracture W 0 remains unchanged after electrical ageing and orientional stretching. The change in the electric strength properties is associated with that occurring in the structure sensitive coefficient κ. The value of W 0 corresponds to the activation energy of the chemical bonds, and it is mainly through these bonds that electrical fracture of the polymers takes place. A mechanism of electrical fracture of polymers is suggested.