Impact of silanized milled graphite nanoparticles on thermo-mechanical properties of epoxy nanocomposite

In the recent past, graphene oxide (GO) or reduced graphene oxides (RGO) as reinforcements showed great potential to improve strength, toughness, thermal stability, and electrical/thermal conductivities of the epoxy composites. The unique structural and physical characteristics of GO or RGO make them better reinforcements for epoxies compared to other carbon-based reinforcements. However, the preparation of GO and RGO is challenging due to the requirement of strong oxidizing agents, prolonged reaction time (-96 h), complicated and costly experimentation setup. This problem can be solved by using milled graphite nanoparticles (GrNPs). The milled GrNPs have a porous structure consisting of stacked and randomly oriented planes with a large number of defect sites. The defect sites make them easy to oxidize within a very short time of 1.5 h. In the present study, economical silanized milled GrNPs were used to improve the thermo-mechanical behavior of GrNP-epoxy nanocomposites. X-ray photoelectron spectroscopy was utilized to confirm the successful silanization of GrNPs by (3-Aminopropyal)triethoxysilane. The epoxy nanocomposite made with 0.5 wt% of silanized GrNP showed an outstanding enhancement in storage modulus of -758% with a considerable improvement of -33% and -43% in tensile strength and fracture toughness, respectively without sacrificing other important properties such as their thermal stability. Thus, an economical milled GrNP can be a good alternative to GO and RGO reinforcements for epoxy resins.