Abstract
Thermally stimulated current in polymethylpentene (PMP) was found to have peaks at about 20°C (referred to as δ peak), 80°C (γ), 110°C (β), and 150°C (α). From the activation energy value or the dependence on biasing electric field, δ peak is considered to be attributable to dipolar depolarization of polar groups caused by glass transition. While carbonyl groups of ester form existing in antioxidants seem to be mainly responsible, hydroperoxide or carbonyl groups formed by oxidation can also contribute to δ peak. The γ peak is caused by the movement of electrons to the electrode from which they were injected. Both β and α peaks seem to be attributable to the motion of hetero space charges.
