Synergistic Enhancement of Mechanical and Thermal Properties in Graphene Oxide/Epoxy Composites via π‐π Stacking‐Induced Ordered Adsorption Layer

ABSTRACT The inherent brittleness of epoxy resin (EP) and its thermal instability at high temperatures represent key challenges hindering its applications in high‐performance engineering. This study demonstrates that non‐destructive modification of graphene oxide (GO) via physical interactions, followed by compounding with EP, effectively addresses these persistent issues by constructing a robust interfacial network. In this study, bisphenol A‐based epoxy resin (E51) and methyl tetrahydrophthalic anhydride (MTHPA) were employed to modify GO without structural damage. An ordered molecular adsorption layer was constructed on the GO surface through π‐π stacking and polar interactions, yielding modified E‐GO. Upon compounding E‐GO with EP, the composite exhibited remarkable improvements in both mechanical and thermal properties. Specifically, at an E‐GO loading of 0.15 wt.%, the tensile strength increased by 249.21%, impact toughness by 170.27%, flexural strength by 56.42%, glass transition temperature by 5.68°C, and weight loss at 800°C decreased by 2.97%. The property enhancement is ascribed to the strong interfacial interaction network: π‐π stacking induces highly crystalline rigid structures to suppress crack propagation, while polar interactions strengthen interfacial bonding. This work provides an effective approach for developing high‐performance epoxy composites with balanced mechanical and thermal properties, highlighting the importance of non‐covalent interfacial engineering in graphene‐based engineering materials.