Abstract: This invention is directed to a process and a novel composition for forming a conductive thermoset material which comprises admixing(a) particles of a polymeric material crosslinked to at least its gel point and swellable at its plasticization temperature,(b) at least one liquid reactive plasticizer for (a)(c) optionally and preferably a curing agent for the reactive plasticizer, and(d) heat or electrically conductive particles, and thereafter heating the admixture for a time sufficient to flux and cure same to obtain a conductive thermoset material. The crosslinking of the thermoplastic polymer can optionally be carried out in a solvent for the polymer. Upon heating, above the plasticization temperature, the liquid reactive plasticizer plasticizes the lightly crosslinked polymer particles. This results in the swelling of the polymer particle, forcing the conductive filler to pack tightly and orderly, thereby increasing the conductivity of the plasticized conductive thermoset after curing.