Electrical Conduction in Medium Viscosity Oil-Paper Films-Part II

The dielectric response of an oil-impregnated-kraft paper system has been examined in the temperature range from 25-85°C at frequencies down to 10-2 Hz. Single and double sheet oil-paper specimens were studied. With single sheet paper specimens the long range charge carrier migration process was found to follow the Eyring behavior over the main test temperature region and was characterized by dc and ac activation energies ranging from 0.40 to 0.47 eV and from 0.37 to 0.48 eV, respectively. The involvement of mobile ions, possibly hydrogen, appeared to be a likely cause for the observed conduction process. Due to appreciable interfacial polarization effects, the dielectric behavior of the two paper sheet specimens exhibited strong deviations from the Eyring behavior. No definite physical significance could thus be attached to the derived values of activation energy over the restricted linear regions of the ln Rac versus 1/T plots.