ENHANCEMENT OF THE ELECTRICAL-CONDUCTIVITY OF POLYPYRROLE FILM BY STRETCHING - INFLUENCE OF THE POLYMERIZATION CONDITIONS

The structure and properties of polypyrrole films prepared by the potentiostatic method (PSM) have been compared to those prepared by the galvanostatic method (GSM). The films contained PF6- as the counter ion. Irrespective of the method used, the conductivity of the unstretched films increased as the preparation temperature decreased. The conductivity of the stretched films prepared by PSM increased monotonically with decreasing temperature, while the films prepared by GSM showed a maximum conductivity at -30 °C. The films prepared by PSM gave higher elongation and conductivity than those prepared by GSM. The film prepared by PSM at -40 °C could be stretched up to 2.7 times its original length and the stretched film showed a conductivity of 3.0 × 103 S/cm in the stretch direction. The structure of the films was determined by Raman spectroscopy, ESR spectroscopy, X-ray diffractometry and scanning electron microscopy. © 1990.