DIELECTRIC-PROPERTIES OF COBALT-DOPED POLY(VINYL ALCOHOL)

Samples of poly(vinyl alcohol) a doped with hydrous cobalt chloride (5 -30%) were prepared by casting. Dielectric measurements were performed at various temperatures and frequencies in order to investigate the e ffect of CoCl2 doping on the relative permittivity (epsilon') and diel ectric loss factor (tan delta) of the polymer. The absorption peaks in the tan delta/T spectra were analysed and interpreted. The low temper ature loss peak was attributed to the cooperative rotational motions o f dipole groups within the main chain and the high temperature loss pe ak to segmental diffusional motion in the amorphous parts of the polym er. Calculated relaxation times and activation energies are discussed in terms of the increase in the inter- and intramolecular interactions due to CoCl2 addition.