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

Abstract

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.