Origins of thermally stimulated current peaks in polyethersulfone investigated through the measurements of space charge distribution

The mechanism of electrical conduction in polyethersulfone (PES) is investigated through the thermally stimulated current (TSC), dc conduction current, and space charge distribution. PES has two TSC peaks below the glass transition temperature of 225 °C. The peak temperature of the lower-temperature TSC, β, increases with an increase in the poling temperature. Through the measurements of space charge distribution by the pulsed electroacoustic method done in combination with the TSC measurements, β peak is considered to be due to ions. Furthermore, the dc conduction current obeys the ionic hopping conduction model, suggesting that the dominant carriers are ions.