Structure and electrical properties of polypropylene-graphite-carbon black/nanotubes hybrid conducting composites

Abstract

(PP) with graphite (Gr) and other carbon black/ nanotubes hybrid materials were investigated. The development of cryst. structure in polypropylene (PP) graphite composite was studied with respect to compn. and processing conditions. The DSC and XRD data confirmed the preferential nucleation and beta cryst. phase formation for the binary PP-Gr composites. There was dramatic increase in the elec. cond. by addn. of small amt. of thrid component (CNT <5%) to the binary PP-Gr composite even at low graphite loading of 10%. Impedance spectroscopy anal. showed that the interfacial capacitance, with the addn. of 2.75 wt% CB in PP-7 wt% graphite, increases to 52 pF from 31 pF for PP-7 wt% graphite proving the occupation of CB particles in the interspaces of graphite particles. The results of elec. cond. were correlated with the nucleation and crystn. of the beta phase of PP by graphite flakes leading to interfacial resistive layer in binary composites while suppression of these effects in the ternary composites