Electrically conductive composites based on epoxy resin with polyaniline-DBSA fillers

A conductive epoxy-anhydride system containing polyaniline (PANI)-dodecylbenzenesulfonic acid (DBSA) has been developed and characterized. Two forms of PANI-DBSA, powder and paste (containing excess DBSA), have shown that excess DBSA in the paste contributes to improved dispersion of PANI-DBSA in the resin, and thus a lower percolation threshold is found. Excess DBSA, however, retards the curing reaction of epoxy/hardener system, but this deficiency can be remedied by using higher accelerator concentrations. Similar trends were found by incorporation of PANI-DBSA coated mica particles, however, the PANI-DBSA engulfed mica particles result in a much lower percolation threshold compared to the PANI-DBSA powder or paste. SEM observation provides useful information for understanding the conductivity behavior of the conductive epoxy systems. Significantly different morphologies are observed for the PANI-DBSA powder and paste dispersed in the epoxy matrix.