Morphology and conductivity of conductive carbon black f illed PP-EAA composites

The conductive composites based on conductive carbon black (CB) , polypropylene ( PP) and poly (ethylene-co-acrylate) ( EAA) were prepared via the melt blending. The dispersion of CB in the two-phase mat rix and theeffect of crystallinity of PP on the conductivity of the composites were discussed. SEM observation indicates that theCB particles were selectively located in the polar EAA resin , which formed a continuous network st ructure in the PPmat rix , resulting in a great decrease of the conductive percolation threshold of the composites. The elect rical testingresult s indicate that compared to the CB/ PP system , the volume resistivity of CB/ PP-EAA composites decreases by7～8 orders of magnitude at the same filler content . PP with higher crystallinity is more favorable for decreasing thevolume resistivity of the composites. Furthermore , the tensile st rength of CB/ PP-EAA composite decreases somewhat compared to the CB/ PP system , while the elongation at break increases.