Enhanced positive temperature coefficient in amorphous PS/CSPE-MWCNT composites with low percolation threshold

In this work, amorphous polystyrene/chlorosulfonated polyethylene composites doped with multiwalled carbon nanotubes (PS/CSPE-MWCNT) were constructed by in situ polymerization to form semi-interpenetrating networks. The MWCNTs showed excellent dispersion and selective location in the PS regions. High electrical conductivity and low percolation threshold (0.89 wt %) for the composites were achieved. An enhanced positive temperature coefficient (PTC) behavior for amorphous PS/CSPE-MWCNT composites was first reported, nearly without a negative temperature coefficient (NTC) effect when the conductive fillers were beyond the percolation threshold, similar to those of crystalline polymer composites. Moreover, a PTC intensity of more than five orders of magnitude and excellent repeatability of the PTC effect were achieved. This study offers new insight into the development of novel PTC materials with low percolation threshold. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47053.