Mechanical properties of epoxy reinforced with homogeneously dispersed carbon nanofibre

This paper investigated the mechanical properties of epoxy reinforced with homogeneously dispersed vapor-grown carbon nanofibres (CNFs) at low concentrations (0.1-0.5 wt%). The homogeneous dispersion of CNF in epoxy was achieved using an optimized dispersion route which was selected among a variety of dispersion techniques. The state of CNF dispersion in the epoxy resin and within the nanocomposites was studied using optical and atomic force microscopy. A detailed investigation on the CNF dispersion behaviour revealed that an ultrasonic treatment assisted with high speed mechanical stirring at 2,000 rpm was very effective in dispersing CNF uniformly in the epoxy resin. Dispersion of CNF up to 0.5 wt% using this route improved the tensile modulus and strength of epoxy by 35% and 63% respectively. Similarly, flexural and compressive properties also improved significantly. Fracture surface of tensile failed specimens was characterized by scanning electron microscopy in order to investigate the fracture mechanism.