Dielectric Properties of Polyimide Film. II. DC Properties

Thermally stimulated depolarization studies, in the absence and presence of applied fields, have shown that polyimide polarizes in both thermal and potential gradients. The conductivity of dry samples has been shown to be due to protons ionized from unreacted polyamic acid, while that of wet samples,1-2 orders of magnitude higher, was found to be due to residual impurity ions.