Novel electroactive polyamide 12 based nanocomposites filled with reduced graphene oxide

Novel electroactive nanocomposites were prepared by adding to a polyamide 12 (PA12) matrix different amounts (from 1 to 8 wt%) of reduced graphene oxide (rGO), and the thermo-electrical behavior of the prepared bulk materials was compared with that of the corresponding fibers. FESEM micrographs on bulk materials highlighted an evident aggregation of the rGO lamellae, proportional to the filler concentration. The presence of rGO stacks was responsible of a heavy embrittlement of the samples, with a strong reduction of the elongation at break, and of the limited electrical conductivity of the samples (about 105 Xcm with a rGO amount of 4 wt%). Moreover, nanofiller addition determined an improvement of the thermal degradation resistance, associated to a slight drop of the glass transition temperature (about 78C with a nanofiller concentration of 4 wt%) and of the crystallinity degree (up to 9% for an rGO loading of 4 wt%). The extrusion process adopted to prepare nanocomposite fibers caused a partial breakage of rGO aggregates and their progressive alignment along the drawing direction, determining thus an electrical resistivity increase with respect to the bulk samples. Therefore, the surface heating of the prepared fibers through Joule effect was possible only at elevated rGO amounts (i.e., 8 wt%).