HETEROGENEOUS DISTRIBUTION OF CARBON-BLACK IN POLYMER BLENDS EFFECT ON CRYSTALLIZATION AND TEMPERATURE-DEPENDENCE OF ELECTRICAL-CONDUCTIVITY

Heterogeneous distribution of carbon black (CB) was observed in the polymer blends of high density polyethylene (HDPE)/polypropylene(PP). From the observation with an electron microscope it was found that the majority of CB particles distribute in the HDPE phase. The DSC cooling curves for HDPE/PP blends and CB-filled HDPE/PP blends shewed that for the blends having a volume fraction of HDPE under 40%, two crystalline peaks of HDPE and PP were observed, and the positions of the two peaks were changed on addition the CB particles. This change confirmed that the CB particles predominantly distribute in the HDPE phase. Also, temperature dependence of electrical conductivity was measured, and the effect of heterogeneous distribution of CB particles in the property was observed.