Polypyrrole-bisphenol A based epoxy composites have been prepared using different amines as hardener systems. The conductivity
was studied as a function ofithe PPy content and compared to carbon black/epoxy composites. The insulator-to-conductor transition was
analysed according to the percolation theory and a model was proposed to fit experimental data of composite resistivity. Direct
observation and image analysis of the conducting composite allowed the determination of the fractal dimension of the polypyrrole
network D and the backbone Da , which were found not to be constant with the filler concentration and were compared with the scaling
theory prediction.