The effect of gamma irradiation on electret properties of polyethylene

The paper describes the electret properties of low-density polyethylene and the effect of gamma irradiation on them. It is shown that the thicker polyethylene film the more stable the surface potential, electric field strength, and effective surface charge density values. The negative impact of gamma-radiation on the electret properties of the films that is caused by the release of the injected charge carriers from the traps due to clearing the energy barrier thanks to radiation energy is revealed. Irradiated polyethylene films, in turn, are polarized badly in a corona discharge because of the oxygen-containing groups on the surface formed during gamma-irradiation that act as charge carrier traps with low capture energy. It was found that the formation of cross bonds in the bulk of the polymer and carbonyl groups on its surface slightly raises the degree of crystallinity and the specific volume resistivity and decreases the specific surface resistivity.