Fluorinated graphite/ZrO2 rigid–flexible heterostructures for improved mechanical strength and lubrication in epoxy composites

Achieving a balance between mechanical robustness and tribological performance in epoxy resins remains a central challenge in polymer engineering. A rigid–flexible coupling design strategy is presented to construct an integrated fluorinated graphite/ZrO 2 (FGZ) heterostructure through controlled intercalation of ZrO 2 nanoparticles. This architected heterostructure simultaneously enhances thermal stability, mechanical properties, and tribological performance in epoxy composites. With only 1.2 wt% FGZ, the resulting composite exhibits a 32.4% increase in thermal decomposition temperature, along with significant improvements in flexural strength (50.1%) and flexural energy absorption (205.3%). In addition, the composite shows a low friction coefficient of 0.1673 and a 64.5% reduction in wear rate under a 15 N load compared to pure epoxy resin, indicating excellent tribological behavior. These improvements are attributed to the synergistic effect of the rigid–flexible heterostructure. In this mechanism, rigid ZrO 2 nanoparticles serve as nanoscale supports that help maintain the structural integrity of graphite layers while promoting progressive delamination. This process facilitates the continuous supply of low-shear fluorinated graphite at the sliding interface, while the released ZrO 2 nanoparticles further contribute to interfacial stabilization and transfer-film reinforcement. This work may provide a useful design concept for multifunctional fillers through cooperative rigid–flexible heterostructures.