Critical Volume Fractions in Conductive Composites

Abstract

An empirical method to predict critical volume fractions for conduction in conductor-filled polymers is presented, based on the idea that a conductive composite can be thought of as a conductive skeleton with its packing geometry determined by the char acteristics of the conductive filler alone. Trends in critical volume fractions can thus be predicted based on the packing behavior of the filler, provided that the filler is well dis persed in the polymer. Critical volume fractions are generally —0.05 below the specific packing fraction for a given filler. All specific rules governing powder packing in general can therefore be applied to conductive composites.