Results of an experimental investigation are presented in which samples of polyacrylonitrile (PAN) were used for thermally stimulated discharge (TSI) of electrically polarized dielectrics. TSD of persistent electrical polarization in dielectric solids is capable of producing a fingerprint ″spectrum″ characteristic of the material being studied. It gives information on temperature ranges over which dipolar parts of molecules become mobile, and as a result some TSD peaks can be correlated with dynamic mechanical and dielectric dispersion data. In the case of PAN, TSD analysis reveals at least four peaks, only two of which (90 degree C and 145 degree C) might be related to molecular mobility effects. The two at higher temperatures must arise from trapped charged species of some kind. A remarkable ability of all but the 90 degree C peak to reappear to various extents in TSD curves from previously depolarized specimens is noted. An interpretation of phenomena observed is offered.
|Original language||English (US)|
|Number of pages||7|
|Journal||Am Chem Soc Div Org Coatings Plast Chem Prepr|
|State||Published - Jan 1 1975|
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