Chemical Origin of Thermally Stimulated Discharge Currents in Poly(Acrylonitrile).
NORTHWESTERN UNIV EVANSTON ILL DEPT OF MATERIALS SCIENCE AND ENGINEERING
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Infrared internal reflection spectroscopy has been used to investigate the origin of thermally stimulated discharge currents 200 C in externally unpolarized films of polyacrylonitrile PAN. Spectroscopic analysis of thermally degraded films reveals the presence of unsaturation in the PAN backbone and an absorption band possibly associated with the presence of cyanide ions. Opposite surfaces in a solvent-cast film give rise to different spectra indicating a gradient in chemical degradation products across the film thickness. Data suggest that non-uniform generation of charged species and unsaturated bonds gives rise to internal potentials in PAN. The origin of thermally stimulated currents in PAN near 200C is thus believed to be associated with the onset chemical degradation. Author