High positive temperature coefficient effect of resistivity in conductive polystyrene/polyurethane composites with ultralow percolation threshold of MWCNTs via interpenetrating structure

Abstract

In this work, a novel interpenetrating system including amorphous polystyrene/polyurethane and multiwall carbon nanotubes (PS/PU-MWCNTs) was in-situ constructed by the homogeneous bulk polymerization. The ultralow percolation threshold (about 0.01 wt%) and high electrical conductivity were achieved owing to the unique conductive networks of MWCNTs in the interconnected “island chain” of PU. Surprisingly, the high positive temperature coefficient (PTC) effect of resistivity of amorphous PS/PU-MWCNTs composites, which was caused by the polymer segment motion, was achieved, such as PTC intensity of six orders of magnitude, fantastic reproducibility and favorable mechanical properties. Finally, this work provided a new promising in the development of excellent PTC materials.