Effect of graphene oxides on the mechanical, thermal, and structural properties of epoxy nanocomposites

This research reports the fabrication of epoxy nanocomposites reinforced with graphene oxide (GO) synthesized via an electrochemical exfoliation method. Epoxy/GO nanocomposites containing 0.5, 1, 2.5, 5, and 10 wt% GO were prepared using a three-roll mill instrument, and their structural, thermal, and local mechanical properties were systematically investigated. Comprehensive characterization included scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, indentation testing, and cyclic indentation testing. The results show that at 2.5 wt% GO, the elastic modulus and hardness increased by approximately 7.4 % and 18 %, respectively, compared to neat epoxy. The glass transition temperature also increased by 24–28 %, depending on GO content. TGA analysis revealed that the residual weight at 800 °C increased from 17.13 wt% for neat epoxy to 26.50 wt% at 10 wt% GO, indicating a ∼ 55 % improvement in char yield and enhanced thermal stability due to the barrier effect of electrochemically exfoliated GO. Cyclic indentation testing further confirmed that 2.5 wt% GO provides optimal performance, offering improved elastic modulus, hardness, and resistance to cyclic loading. These findings highlight the potential of electrochemically exfoliated GO/epoxy nanocomposites for applications in aerospace, automotive, and advanced electronic devices.