Electrical Conductivity of Pyrolysed Polyamides Derived from 1,4-Bis(2-Cyano-2-Carboxyvinyl)Benzene and Various Aromatic Diamines

Abstract

The electrical conductivity of three homopolyamides, synthesized from aromatic diamines and identified as PAM, PAP and PAS, was investigated as a function of temperature in the range 100–700 K, following pyrolysis for 24 h in an atmosphere of N₂ at temperatures of 550, 700, 800 and 850 °C. X-ray profiles were recorded for the three polymers before and following pyrolysis. The non-heat-treated polymers are amorphous whereas a certain degree of crystallinity is observed following pyrolysis. The observed conductivity covered a range from 10⁻⁹ to 10 S cm⁻¹ depending on the polymer and the pyrolysis temperature. The results suggest that the conductivity is thermally activated and is due to two mechanisms, the intra-chain conductivity and the inter-chain conductivity. The activation energy for the intra-chain mechanism varies from 0.36 to 0.01 eV and for the inter-chain mechanism the activation energy varies from 2.76 to 0.08 eV, depending on the pyrolysis temperature for both mechanisms.