Fabrication of highly ordered polymer/graphite flake composite with eminent anisotropic electrical property

Highly ordered polyester/graphite flake composite has been fabricated via orienting the graphite flakes within a polymer matrix. The randomly dispersed graphite flakes in a polyester prepolymer were induced twice along the electric field direction, followed by the cross-linking of the prepolymer. Scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis showed that the graphite flakes in the resulting composites were aligned parallel to each other. This structure anisotropy of the composite appeared to be a significant electrical anisotropic property with five to six orders of magnitude. Analysis showed that field-induced torque caused by the polarization of graphite flakes undergone at electric field was a main force inducing the orientation of the graphite flakes. Copyright (C). 2008 John Wiley & Sons, Ltd.