Fabrication and characterization of graphene oxide and glass fiber-based hybrid epoxy composites

This work aims to develop and characterize graphene oxide (GO) and glass fiber (GF)-based hybrid epoxy composites. Graphite oxide was synthesized by improved Hummers' method, and it was uniformly dispersed in ethanol by ultra-sonication to form GO suspension. Later, GO and GF-based hybrid epoxy composites were prepared by hand layup method followed by curing under compression to develop composite sheets accordingly to the ASTM standards (D3039 & D6110-18). Fourier transform infrared spectra of the neat and the GF-based hybrid epoxy composites confirmed the formation of improved interface between GO/epoxy and silane coating present on GF surface, which is well validated with the given reaction schematic. Scanning electron microscope and elemental mapping results corroborate our point that the GO filled the voids and empty spaces and lessened the water absorption properties of the composite which is much needed for the application of composites at high altitudes and marine environment. Effect of GO content on mechanical properties of prepared composites was studied by varying the GO content from 0.1 to 1.2 wt%. Mechanical characterization of GO and GF-based hybrid epoxy composites were carried out by tensile and impact testing. Ultimate tensile strength, impact strength and elongation were increased by ~20%, ~41%, and ~19%, respectively, at 0.4 wt% addition of composition. The avg. delamination factor for this composition (0.4 wt% of GO) reduced as compared to neat epoxy and other wt% compositions for 6-, 5-, 4-, & 3-mm drill bit sizes.