THE CONDUCTING BEHAVIOR AND STABILITY OF CONDUCTING POLYMER COMPOSITES

Results of measurements of the electrical conductivity of low density polyethylene/polypyrrole and polystyrene/polypyrrole composites are re ported. It is observed that the electrical conductivity of the composi te vs. concentration follows the power law predicted by the percolatio n theory. The manufacturing process influences the homogeneity of the composite at microscopic scale and thus the percolation threshold. Ann ealing studies show that the stability of the electrical conductivity of the composite is related to the thermal expansion of the polymers a nd the relaxation of the polymer chains. The decrease of the electrica l conductivity of the composite is attributed to the interruption of t he percolation path.