Ionic DC transport in polyetheretherketone

The dc conduction process in polyetheretherketone is discussed from the results of thermally stimulated current (TSC). In TSC spectra, a peak appears at a temperature of about 5-20/spl deg/C above the biasing temperature and approaches to the constant temperature of 155/spl deg/C when the biasing temperature is higher than 150/spl deg/C. This peak shows the maximum value at 155/spl deg/C when the biasing temperature is 150/spl deg/C. It is considered that this peak is related to the glass transition and caused by the depolarization of an ionic space charge. A drastically increasing current is also observed at temperatures over 180/spl deg/C. It is considered that this current is attributed to a spurious current which is spontaneously generated even in a non-biased sample. Both the large current at high temperature and the above mentioned peak in TSC are thought to be related to ionic carriers which may come from by-products of synthesis. This result is consistent with the dc conduction process, which is mainly due to ionic transport.<>