Electrical properties of polyethylene and carbon black particle blends prepared by gelation/crystallization from solution

Composite materials based on low molecular weight polyethylene (LMWPE), ultra-high molecular weight polyethylene (UHMWPE) and carbon black (CB) particles were prepared by gelation/crystallization from solution. The positive temperature coefficient (PTC) intensity for the 90/10 (LMWPE/UHMWPE) composition exceeded five orders of magnitude for the specimens heat-treated at a suitable temperature, which was almost equal to that observed with LMWPE-CB blends prepared by a kneading method. In comparison with LMWPE-CB blends, much promoted reproducibility of PTC effect and inhibition of the negative temperature coefficient (NTC) effect were achieved.