Electrical and dielectric behaviors of dry-mixed CNT/UHMWPE nanocomposites

Carbon nanotube (CNT)/ultrahigh-molecular weight polyethylene (UHMWPE) nanocomposite with an electrical percolation threshold of only 0.1 wt% was prepared by simple dry mixing followed by compression molding. The nanocomposite microstructure, direct current and alternating current (AC) electrical conductivities, conduction mechanisms, and dielectric properties in the 10(1)-10(5) Hz frequency range have been investigated. Due to the localization of the nanofiller at the surface of UHMWPE powder particles, a segregated microstructure within the polymer matrix was created. Nanocomposites filled with 0.125-0.5 wt% CNT were found to follow the typical universal dynamic response behavior, and the characteristic frequency was found to increase with the increase in CNT concentration. At CNT concentration >= 0.5 wt%, the AC conductivity was found to be frequency independent over the entire frequency range studied.