The study of the geometrical structure of the
percolation network is clearly the first step to understand
physical properties such as macroscopic conductivity. The
morphology of the PPy network in the DGEBA/lPD,TMCA
epoxy matrix has been studied using optical microscopy and
transmission electronic microscopy. A detailed image analysis of
the micrographs has been performed. Afier digitizing, the grey-
leveled images were converted into binary picture through a
careful thresholding transformation. Then the fractal dimension
D of the conducting network has been determined through the
successive square method6 based on the self-similarity of the
structure between a microscopic length c1 and the correlation
length 5, that is described by the following power law: