Electrical and rheological behaviors of VGCF/polyphenylene sulfide composites

The effect of vapor grown carbon fiber (VGCF) contents on electrical and rheological properties of VGCF filled polyphenylene sulfide (PPS) composites prepared through melt mixing using a twin screw extruder was studied. This method was proved to be quite effective to produce good dispersion of VGCF in the matrix even for highly filled PPS. From the dependence of the electrical conductivity on VGCF content, the percolation phenomena began to occur above 1C wt%. While there is only a marginal increase of viscosity for 1 and 5 wt% VGCF filled PPS, the composites containing 10 wt% VGCF showed abrupt increase in viscosity as well as flattening of frequency vs modulus curve, indicating a transition from a liquid-like to a solid-like behavior due to the creation of VGCF network. This result agrees well to the fact that the network formation in the composite can be confirmed by rheological property dependence on filler content as well as by electrical conductivity measurement.