Graphenes for low percolation threshold in electroconductive nylon 6 composites

Abstract

Moderately functionalized graphenes, prepared by the thermal reduction of graphite oxide, were utilized to prepare electroconductive graphene/nylon 6 composites which exhibited a highest conductivity value of 6.84 × 10−4 S cm−1 for a low carbon incorporation of 0.54 wt% and a lowest percolation threshold of 0.39 wt%, the lowest values reported so far for graphene/nylon 6 composites. The functionality of the graphenes was modulated by the thermal reduction time. The graphitic structure of graphene was strengthened by extended thermal treatment. The main strengthening mechanism in the first 5 min was the generation of new sp2 domains followed by the growth of the domains during the next 5 min. This extended thermal treatment improved the conductivity of the graphene itself as well as the composite loaded with graphene. However, it led to poor dispersion of the graphene in the composites, reduced crystallization of nylon 6 and reduced reinforcement of nylon 6 by graphene. © 2013 Society of Chemical Industry