Enhanced Tribological Properties of PBO/Polyimide Composites Containing GO Interfacial Phase

Polyimide (PI) materials are highly valued in tribological applications due to their excellent friction-reduction and wear-resistance properties under extreme conditions. However, their relatively low tensile properties limit their effectiveness as standalone materials, necessitating reinforcement. Poly(p-phenylene benzobisoxazole) (PBO) fibers, known for their superior mechanical and tribological properties, struggle with effective interfacial bonding with PI due to low surface activity. This gap in effective reinforcement strategies is critical for advancing PI applications. Here, we address this challenge by anchoring graphene oxide (GO) nanosheets onto PBO fibers using rare-earth (lanthanum) ions, producing RE-GO-RE-PBO fibers with a multi-scale reinforcement structure. The study involved optimizing the rare-earth solution (RES) concentration and characterizing the fiber surfaces. Our results indicate that an optimal RES concentration of 0.3 wt% achieves uniform and stable GO deposition, significantly enhancing interfacial bonding with the PI matrix. The resulting RE-GO-RE-PBO/PI composite exhibited a 91.74% increase in tensile strength and a 58.44% increase in modulus compared to pure PI, alongside improved wear resistance and a low friction coefficient. These findings present a novel strategy for designing high-performance tribological composites by integrating rare-earth-modified nanomaterials into fiber-reinforced matrices. This approach not only addresses the critical challenge of enhancing interfacial bonding but also provides a theoretical and experimental foundation for advanced applications in aerospace and other high-tech sectors, pushing the boundaries of tribological material performance.