Abstract: Polystyrene (PS), styrene-acrylonitrile copolymer(SAN), and methyl methacrylate-styrene copolymer(MS) were separately melt mixed with polycarbonate (PC) and multiwalled carbon nanotubes (MWCNTs) leading to three to composites, PC/PS/MWCNTs, PC/SAN/MWCNTs, and PC/MS/MWCNTs. The distribution of MWCNTs in the composites were examined uisng transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). It was found that MWCNTs were prefrably localized in PC phase, which was in agreement with Sumita's model. With increasing contents of PS, SAN or MS, the curves for resistivity of the composites versus contents of styrene-based polymer agreed well with curves for resistivity of PC/MWCNTs composites versus effective volume concentration of MWCNTs, which was in accordance with the concept of effective volume concentration.

Key words: multiwalled carbon nanotube, polycarbonate, styrene-series polymer, conductivity