Poly(acrylonitrile-co-butadiene-co-styrene) (ABS) is a thermoplastic polymerthat is used in numerous structural applications as a result of itsexcellent mechanical properties. For those applications where goodelectrical conductivity is also desired, carbon black is often used as thefiller of choice. Most reports in the literature indicate that at least 8wt% carbon black filler is needed in order to achieve percolation. Our grouprecently reported that by manual mixing of ABS pellets and carbon black tocreate a segregated microstructure, percolation was achieved at anunprecedented low filler fraction of less than 0.01 wt% carbon black, avalue which is comparable to or even better than that obtained using singlewall carbon nanotubes as the filler. While the ABS/CB composites hadexcellent electrical performance, with a conductivity as high as 10-1 S/m,their mechanical strength was compromised.

In this paper we report on new experiments designed to maintain highelectrical conductivity while improving on the mechanical behavior ofpercolating ABS/CB nanocomposites. The experiments were aimed at controllingthe processing parameters such as temperature, pressure and time during hotpressing of the mechanically mixed precursor materials. Using data obtainedat the various temperature-pressure combinations used, it will be shown thatsimilar volume percentages of carbon black and carbon nanotubes can be usedto obtain equivalent conductivities, suitable for EMI shielding, while stillmaintaining good mechanical properties.