ELECTRICAL-PROPERTIES OF PLASTIC COMPOSITES USING BR2-INTERCALATED VAPOR-GROWN CARBON-FIBERS AS A CONDUCTIVE FILLER

Graphite fiber intercalation compounds were prepared by immersing graphitized thin vapor-grown carbon fibers (VGCF's) with diameters less than 0.5 mum into liquid bromine. The composition of Br2-intercalated VGCF was C70Br-C90Br. The powder resistivity of Br2-intercalated VGCF was estimated as 1/3 of pristine VGCF. An electroconductive plastic composite was prepared by mixing phenol resin with that of bromine intercalated VGCF as a conductive filler, and its electrical properties were investigated. The resistivity of a Br2-intercalated VGCF composite was 1.1 X 10(-2) OMEGA . cm at room temperature, which is about 50% of pristine VGCF composite. Br2-intercalated VGCF-based composite had a high degree of stability against exposure at 150-degrees-C in air and at 85-degrees-C with 90% humidity for 500 h. Br2-intercalated VGCF-based plastic composites could be used as highly electroconductive materials.