Electrically conductive composites based on epoxy resin containing polyaniline-DBSA- and polyaniline-DBSA-coated glass fibers

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. (C) 2003 Wiley Periodicals, Inc.