Effect of oxidants and anionic surfactants on the morphology and permittivity of polypyrrole and its blends with epoxy resin

Abstract

In this work, conductive polymers were prepared based on polypyrrole (PPy) and its blends with epoxy resin. The chemical syntheses of PPy used two oxidants (Fe2(SO4)3 and FeCl3.6H2O) and two surfactants (DBSNa and DBSA). PPy samples and their blends were characterized by scanning electron microscopy, electrical conductivity by four points, and measurements of complex parameters of electric permittivity (ϵ) and magnetic permeability, in the frequency range of 8.2 to 12.4 GHz. The micrographs of the fractured surfaces show that the PPy synthetized in the presence of surfactants has particles with smaller diameters, and the oxidant sulfate favored the formation of elongated structures, called fillets. The analysis of the blends found a homogeneous distribution of PPy clusters in epoxy resin matrix, which did not favor the electrical conductivity of these materials. On the other hand, the measurements of the complex parameters of the permittivity show that the blends have increasing values when the PPy concentration is increased in the epoxy resin.