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Four kinds of polyaniline (PANI)-coated glass fibers (GF-PANI) combined with bulk PANI particles were synthesized. GF-PANI fillers containing different PANI contents were incorporated into an epoxy-anhydride system. The best conductivity behavior of the epoxy/GF-PANI composites was obtained with a GF-PANI filler containing 80% PANI. Such a composite shows the lowest percolation threshold at about 20% GF-PANI or 16% PANI (glass fiber-free basis). The PANI-coated glass fibers act as conductive bridges, interconnecting PANI particles in the epoxy matrix, thus contributing to the improvement of the conductivity of the composite and the lower percolation threshold, compared with that of a epoxy/PANI-powder composite. Particularly, the presence of glass fibers significantly improves the mechanical properties, for example, the modulus and strength of the conductive epoxy composites.

This paper is an extension of previous work on polymerization of anilinium±DBSA (dodecylbenzenesulfonic acid) in an aqueous dispersion in the presence of mica or talc silicate particles. The presence of mica or talc particles greatly accelerates the polymerization process of anilinium-DBSA and an encapsulated structure is formed as well. The catalytic effect of various metallic cations which exist in the chemical compositions of mica or talc on the polymerization kinetics of anilinium-DBSA was investigated. The conductivity results along with microscopy observations prove a well formed encapsulated structure for the polyaniline/mica composites, but less for the polyaniline/talc composites. The anilinium-DBSA complex and mica aqueous dispersions pretreated at different temperatures prior to polymerization have shown a significant effect on the polymerization rate of anilinium-DBSA. The higher the dispersion temperature, the higher is the polymerization rate found.