Electrical properties of surfaces of unirradiated and irradiated polymers in humid environments

The behavior of surface charge decay of corona-charged polyether ether ketone (PEEK) and polypropylene (PP) for different charging potentials is reported in this work. The nature of the charge decay with PEEK shows a presence of two processes involving a fast decay which is followed by a slower process. The fast decay process may originate from a field-induced dielectric polarization while the slow process arises from a thermal hopping process. The charge decay with PP was found to be quite insignificant over an extended period of time. The adsorption of water of these two polymers with and without gamma irradiation (6 Mrad) have also been measured over a range of humidity (RH%). The adsorption was observed to be enhanced for PEEK with gamma irradiation, whereas for PP it was significantly reduced