Mechanical Properties of Multiscale Graphene Oxide/Basalt Fiber/Epoxy Composites

This work was carried out to study the effects of silane functionalization of graphene oxide (GO) nanoplatelets and their loadings on the mechanical properties of basalt fiber (BF)/epoxy composites. At first, the GO nanoplatelets were organically modified by grafting of N-(3-trimethoxysilylpropyl)ethylenediamine (3-TMSPED) compound. The Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and thermal gravimetric analysis (TGA) results demonstrated that silane compound can be covalently grafted to the surface of GO. The multiscale silanized graphene oxide (SGO)/BF/epoxy composites with various weight percentages of SGO in the matrix (0-0.5 wt.% in the step of 0.1) were fabricated. According to the experimental data, the 0.4 wt.% SGO-filled composite showed the maximum improvement by 18 %, 59 %, and 61 % in the tensile, flexural and compressive strengths of BF/epoxy composite, while the maximum improvement by 46 %, 54 %, and 66 % in the tensile, flexural and compressive moduli, respectively was observed for the 0.5 wt.% SGO-filled composite. Additionally, the SGO was more effective in mechanical property enhancement of fibrous composites in comparison with GO, due to its silane-functionalization. From the fracture surface examination of the specimens, it was found that the incorporation of GO or SGO improved the BF-epoxy interfacial bonding. A theoretical model based on Euler-Bernoulli beam-based method was utilized to predict the compressive properties of composites, which was in an excellent agreement with the experimental data.