The electrical conductivity and breakdown phenomena in polyester polymer-quinoline salt of tetracyanoquinodimethane composites

The author studied the influence of the length of the conducting particle of the filler on the electrical conductivity of the composites obtained by embedding into polyester polymer needlelike conducting crystals of quinoline salt of tetracyanoquinodimethane. The results clearly demonstrated the importance of shape factors for the formation of a conducting network and percolative charge transport in composite systems. The results are in agreement with the previous data, which have shown that very low values of threshold contents of conducting fillers are observed for large particle-length-to-diameter ratios. Other results confirmed the assumption that the decrease of electrical conductivity of samples after the critical field is exceeded is caused by breaks of the conduction network at the weak points, and that the electrical conduction of low-conduction samples is probably dominated by injection of charge carriers, fluctuation-induced tunneling, and prebreakdown effects.<>