Improvement of mechanical and electrical properties of epoxy resin with carbon nanofibers

In the present research, the reinforcement effect of vapor grown carbon nanofiber (VGCNF) was studied in relation to the mechanical properties and electrical conduction behavior of fabricated nanocomposites. Different weight fractions of nanofillers into epoxy resin, from 0.05 to 1 wt% and up to 2 wt% for mechanical and electrical properties were investigated. It was found that the optimum improvement in mechanical properties of nanocomposite is obtained at 0.25 wt% of carbon nanofibers. At this filler content, 23 % enhancement in tensile strength and 10 % in flexural strength have been observed. The degree of the VGCNF dispersion has been monitored by means of viscosity variation of the suspension during the sonication process to obtain the optimum sonication time. Finally, the quality of the dispersion for post-cured nanocomposites is characterized by fractured surfaces using the scanning electron microscopy. Agglomerates had a direct effect on the reduction of tensile and flexural strength of nanocomposites. The electrical conductivity was obtained by means of surface measuring method. The optimum amount of filler for the generation of a fine electrical conductivity was found to be around 0.5 wt% of VGCNF. After the threshold point, the electrical conductivity of nanocomposites was slightly raised in spite of adding more filler contents.