Impact of the Impurities on the Conductivity of Low-Density Polyethylene

In this study, the byproduct-driven conduction current in LDPE was investigated. We built an experimental fixture to measure bulk conductivity in LDPE soaked with byproducts. Ohmic conduction was observed below 10 kV/mm. At above 10 kV/mm, space charge limited current (SCLC) predicts observed conduction in LDPE soaked with byproducts. It is found that the addition of byproducts introduces charge traps with discrete energy levels which dominate conduction. Degassed samples, on the other hand, show slopes of greater than 2.5 in a current-voltage log-log plot which was attributed to the charge traps with continuous energy levels. By analyzing the thickness dependence of the current, we observed a transition from electrode- to bulk-limited current at above 20 kV/mm for acetophenone- and α-cumyl alcohol-soaked samples. The α-methylstyrene-soaked samples only show electrode-limited current.