AbstractThermally stimulated depolarization of cellulose nitrate has been measured as a function of polarizing voltage, electret forming temperature, heating rate and storage time. A single peak due to polar side ester group is observed at approximately 50°C, whose magnitude increases with polarizing voltage. The peak is absent for low (≤90°C) and high (≥140°C) electret forming temperatures. In the intermediate temperature range the value of the peak current decreases with the forming temperature from 100 to 120°C and then increases. The magnitude of the peak current and the peak temperature increase with heating rate and decrease with stora