Electrical properties of CNFs/epoxy-amine resin for aeronautic and aerospace applications

In this paper we have tried to increase the electrical conductivity of CNFs by reducing the defects on the nanofibers with the aim of increasing electrical conductivity of nanofilled/epoxy resins in such a way as to overcome some drawbacks related to the electrical insulation properties of epoxy resins used in the field of aeronautic materials. Heat treatment of carbon nanofibers has proven to be an effective method in removing defects from carbon nanofibers causing a strong increase in their structural perfection and thermal stability. Nanocomposites made of heat-treated CNFs dispersed inside an epoxy-amine mixture specifically designed for structural applications show significant increase in the electrical conductivity even at low concentration of nanofiller. Heat-treated CNF displays stiff structure and smooth surface which tend to lower the thickness of the unavoidable insulating epoxy layer formed around CNF which, in turn, plays a fundamental role in the electrical transport properties along the conducting clusters. The heat treatment of CNFs is very beneficial in terms of electrical conductivity but not in terms of mechanical properties which, in any case, were comparable to the properties of the unfilled resin