Effect of Polarity on Volume Conductivity of Polymers, Determined by Corona Triode Method

In this paper, the effect of polarity on the volume conductivity of Kapton and polyethylene (PE), determined using the corona triode method, when the sample current depends linearly on grid potential, was studied. For the determination of volume conductivity, in addition to the analytical method, for the first time, a graphical method is presented as well. According to the experimental results, obtained by both methods, the volume conductivity values of negative corona charged samples were higher than those of the samples charged by positive corona. Considering the different nature of positive and negative coronas, these differences in results are to be expected and are in full accordance with the theoretical considerations as well. On the other hand, the good agreement between the analytical method results and those obtained by the graphical method, indicates high accuracy of the proposed analytical formula. Meanwhile, the satisfying accordance of experimental results with those found by the classical “static” and “dynamic” methods, confirms the accuracy of the corona method, for the determination of volume conductivity of polymers.