Research on the PTC properties of polyethylene/carbon black composites

The influence of carbon black and polyethylene on the conductance and the PTC properties of polyethylene/carbon black composites is investigated. I-V characteristics of the composite are also measured. Experimental results show that the PTC properties of a sample containing carbon black are not evident and the conductance of the composite is attributed to the tunneling current of intergrain gaps between carbon black particles. The phase change model is used to explain the phenomenon of PTC and NTC well.