Enhanced mechanical and electrical properties of nylon-6 composite by using carbon fiber/graphene multiscale structure as additive

In order to improve the mechanical properties and electrical conductivity of nylon-6 (PA6) composites, a highly effective multiscale structure filler comprising poly(diallyldimethylammonium chloride) (PDDA)-modified graphene and negatively surface-charged carbon fiber was synthesized in this study. For this, the graphene used a top-down method for synthesis by exfoliating graphite oxide (GO) through focused solar radiation on it and then modified its surface by using a polyelectrolyte. The carbon fiber (CF) surface was functionalized by an acid oxidation method. The multiscale structure was manufactured via the electrostatic interaction between the positively charged solar graphene (SG) and oppositely charged CF by homogeneous mixing. Scanning electron microscopy (SEM) images of the fracture surface of the PA6 composites exhibited that the carbon fiber/graphene multiscale structure possessed better dispersion and compatibility than those of individual CF and SG did. Thus, the impact strength, bending properties, and electrical conductivity of the PA6 composites were enhanced.