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Undoped and chlorine doped difluoraniline polymers (PDFA) were synthesized and characterized to study the electric behavior of polyanilines with three different fluorine disubstitutions in the benzene rings that could produce polarizable molecules. The structures of the resulting polymers were studied by infrared spectroscopy focusing in the oxidation degree in the polymers. A discussion of the molecular weight of PDFAs as measured by light scattering in different solvents is presented, since the polymers form aggregates depending on the solvent used, the position of the fluorine substitutions, the doping level and the temperature. The aggregates in polarizable polymer solutions can produce wrong estimations in the molecular weight if the influence of temperature is not considered. The PDFAs thermal and electroconductivity analysis also showed dependence on the position of the fluorine substitutions.

Percolation in carbon black‐filled polymeric concrete, is discussed based on the measured changes in electrical conductivity and morphology of the composite at different concentrations of carbon black. The percolation threshold ranged between 6 and 7 wt% (based on resin weight) of carbon black. Above this concentration, the filler particles formed agglomerates in contact with each other, suggesting that the conduction process is nearly ohmic in nature. A power law predicted by percolation theory described the behavior of the conductivity as a function of carbon black content. Microscopic analysis showed the presence of a continuous structure formed by the polyester resin and carbon black, in which silica particles were embedded.