Surface partial discharges aging on thin polymeric nanocomposite films

The following study evidences the effects of surface partial discharges aging on thin polymeric films in specific ambient conditions. The study has been performed on syndiotactic polypropylene and its nanocomposites. The specimens have been prepared by adding two different nanofillers to the pure polymer: montmorillonite and sepiolite, which are both silicate clays. In order to obtain a good dispersion of the considered nanofillers inside the matrix, the nanostructured materials have been prepared by extrusion. The nanofiller dispersion has been analyzed by means of a scanning electron microscope. Electrical breakdown strength measurements have been performed and surface partial discharges aging tests have been carried out inside an environmental chamber in order to control both the relative humidity level and the temperature. The specimens breakdown condition has been chosen as end point criterion and the concerning times to breakdown have been collected and compared in order to evidence the different behavior among the pure polymer and its nanocomposites.