study of the thermally stimulated depolarization current (tsdc) for composites of acrylonitrile butadiene rubber (nbr) loaded with haf

the thermally stimulated discharge (tsdc) current is studied for acrylonitrile butadiene rubber (nbr) loaded with different high abrasion furnace carbon black (haf). tsdc peak appears only for higher haf contents > 60phr (70 and 80phr of haf contents), the tsdc spectra consist of a sharp peak corresponding to a peak temperature tm which is slightly shifted to higher temperature for 70phr loaded nbr samples and to lower temperature for 80phr loaded nbr sample, with poling field (10v/cm to 50v/cm). the activation energy     u and relaxation time      for tsdc peak were calculated using the initial rise method. the calculated values of u are nearly constant for sample 70phr and slightly increase for sample 80phr with increasing poling field     ep . the calculated values of      at peak temperature tm are nearly constant for two samples (70phr & 80phr) with different poling field, whereas the calculated values of relaxation time      at to = 300k increased with increase of poling field.