Analysis of the impact of exfoliated graphene oxide on the mechanical performance and in-plane fracture resistance of epoxy-based nanocomposite

Graphene oxide (GO) is a versatile material, derivative of graphene, and it has gained significant attention in the field of polymer nanocomposites due to its exceptional properties and unique structural features. These characteristics make it a successful secondary reinforcing agent for enhancing mechanical performance, fatigue resistance, and other various physical and thermal properties of nanocomposites. However, the low fracture toughness of nanocomposite has restricted the overall structural applications. In this research work, the epoxy nanocomposites were prepared with different weights of exfoliated graphene oxide (E-GO) nanoparticles by using a dual mixing probe ultra-sonication for homogeneous distribution and proper dispersion. A substantial enhancement in mechanical performance and fracture toughness of nanocomposite was observed. The good dispersion and interfacial adhesion among E-GO and epoxy matrix were investigated through the critical analysis of the fracture surfaces of the nanocomposite. The enhancement of mechanical performance of E-GO nanofiller-reinforced epoxy composite was observed superior at 1 wt. % of GO60 particle concentration. The maximum increment of mechanical properties such as tensile strength, flexural strength, and work of fracture were 40.763, 39.23, and 12.106 % respectively, whereas maximum tensile modulus and flexural modulus were 19.3724, 27.63 % at 1.5 wt. % of GO60 as compared to the neat composite. However, in the case of fracture toughness and energy, maximum improvement of 1.256 Mpa.m1/2 and 0.472 KJ/m2 respectively was observed at 1 wt. % of GO60. Such enhancement was primarily due to the bolstering of in-plane crack propagation resistance in the nanocomposites. Additionally, the highlight point in thermomechanical properties of the polymer nanocomposite is optimal storage modulus and damping factor such as 4066.75 MPa, and 0.46 respectively, for the GO60 at 1 wt.% nanocomposite. Moreover, GO60 at 1 wt.% demonstrates greater thermal stability, withstanding up to 50% material degradation at 413.65°C.