Effect of doping on TSD relaxation in cellulose acetate films

Thermally stimulated depolarization current (TSDC) studies have been perfor med on solution grown cellulose acetate films doped with different concentr ations of acrylic acid (AA) prepared at the poling temperatures (40-75 degr eesC) with poling fields (10-50 kV/cm). The TSDC spectra of pure and AA dop ed CA films reveal two relaxation peaks at 80 degreesC and 180 +/- 2 degree s C, having activation energies centred around 0.25 and 0.55 eV. The phenom ena of the existence of these current maxima have been analyzed and discuss ed in terms of the molecular motion of the polar side groups and release of the remaining part of the frozen dipoles by their cooperative motion with adjoining segments of the main polymer chain. The peak currents, released c harge and activation energies associated with the peaks are affected by AA doping. The effect of doping with acrylic acid on the discharge current ind icates the formation of molecular aggregates.