Dependence of surface conduction current in oxidized polyethylene on electric field at various humidities

The voltage dependence of the surface conduction current in pure and oxidized polyethylene has been investigated at various relative humidities and at room temperature. The surface conductivity of pure polyethylene has been confirmed to be less than 10 -19 mho at near saturated water vapour pressure at 25 degrees C. It has been observed that the surface conduction current of oxidized polyethylene increases in proportion to the square of voltage in the high voltage range at high humidity, where the increase of the current with humidity has been suggested to be due to the increase of carrier mobility.