Resistivity and crystallization behavior of saponified EVA/carbon black and EVA/graphite composites

초록

Polymeric electro-conductive materials usually employ thermo-plastic polymer or elastomer as a matrix for dispersion of electro-conductive fillers including metal powders, such as Al, Au, Ag, andCu. Carbonfiber,carbonblack(CB) and graphite(GP) are also frequently employed as conductive fillers. These materials are widely used as contact point materials for electrostatic charge dissipation, surface heaters, EMI shielding, and contact switches. This is mainly due to their positive temperature coefficient(PTC) of resistivity. It has been well accepted that the strong PTC effect of electro‐conductive filler filled polymer is caused by an increase in the average interparticle or aggregate distance of filler, which is created by the large thermal expansion that occurs as a result of the melting of the polymer crystals. In this study,Poly(ethylene-co-vinyl alcohol)(EVOH)/CB and EVOH/GP electro-conductive composites were prepared by simple saponification method in ethanol/KOH solution. Morphology, resistivity and crystallization behavior of the prepared composites have been evaluated.