Transient behavior of electrical conductivity in low-density polyethylene in the presence of acetophenone

The transient current in low-density polyethylene (LDPE) is studied, particularly in the presence of the small organic molecule acetophenone (ACP). Crosslinked LDPE is used extensively in high-voltage power transmission, and acetophenone is a common byproduct of the crosslinking chemistry. Time-dependent current measurements of LDPE with and without ACP soaked into the polymer as well as at one or both electrodes are performed by applying step voltages. The results demonstrate that the presence of ACP causes a deviation in the predicted power-law current decay, suggesting that electron and hole injection at the anode and cathode, respectively, are affected by the presence of this small organic molecule. ACP contributes both to the ionic conduction and charge hopping mechanism. The charge mobility depends on the applied electric field and the sample thickness. The results suggests that the dispersive charge transport phenomenon influences the measured current. This study shows how such a molecule may alter charge transport in polyethylene.