DC CONDUCTION IN CHLOROPRENE RUBBER (CR)

The time and temperature dependence of DC and electrical conductivity of vulcanized and fresh samples of crystalline CR have been investigat ed. The conduction has been found to occur by an ionic mechanism. The existence of ionic conduction is supported by the appearance of a peak in the current-time curves after the reversal of the polarity of the applied voltage. An anomalous behaviour was observed in the temperatur e dependence of the electrical conductivity and was attributed to the phase transition of CR from the crystalline to the amorphous state. It was also found that vulcanization increases the mobility of the curre nt carriers and hence the electrical conductivity. On the contrary the milling process decreased both mobility and conductivity.