Abstract
Thermally stimulated current (TSC) spectra of polyacrylonitrile were measured for temperatures ranging from 10 to 170°C. The TSC spectrum obtained with the polarization in a low polarizing field is characterized by two peaks at 110°C (αI peak) and at 150°C (αII peak). In the case of the high field polarization, a current reversal phenomenum was observed near at the αII peak temperature. It is considered that the αI and αII peaks are due to the dipolar relaxations in the amorphous and paracrystalline phases, respectively. The activation energies for these two dipolar relaxations were determained by thermal sampling method. The values obtained were 36 kcal/mol for the αII relaxation and 43 kcal/mol for the αI relaxation. The degree of crystallinity, which was calculated as a percentage of the polarization charge responsible for the αII relaxation against the total polarization, was 32%.
