Synergistic effect of conductive carbon black and silica particles for improving the pyroresistive properties of high density polyethylene composites

Abstract Smart heating devices, assembled by the conductive polymer composites (CPCs) with positive temperature coefficient (PTC), have been wildly used in automobile, spacecraft, smart building, due to their outstanding self-regulating performances. Unfortunately, the intrinsic drawbacks of CPCs such as resistance instability and poor PTC reproducibility vastly restrict the prosperity of smart heaters. Herein, a facile and valid strategy based on doping silica nanoparticles in conductive carbon black (CB)/high density polyethylene (HDPE) composites is proposed to enhance the comprehensive PTC properties. The synergistic effect of conductive CB and silica, evidenced by the simultaneously enhancement of the conductivity, resistance stability and PTC reproducibility of Silica/CB/HDPE composites, has been demonstrated as the content of silica reaching 3.0 vol % when CB loading is just above its percolation threshold. Our morphology studies suggest that this effect is attributed to the improved dispersion of CB with the intercalation of silica particles. It is believed that this work offers a facile and low cost method for fabrication of high-performance self-regulated heating material.