Constructing a “brick and mortar” structure to synchronously strengthen the mechanical and tribological properties of fabric laminated composites by isocyanate functionalized carbon fiber powders

Fabric laminated composites with excellent mechanical strength and brake stability are now developed as promising wet friction materials. However, facing the serious challenge of persistent operation under harsh conditions, the resistance and interlaminar bonding properties of laminated composites urgently require further improvement. In this study, methylene diphenyl diisocyanate (MDI) was chemically grafted onto a carbon fiber powder (CFP) surface via an oil bath for surface functionalization. Fabric laminated composites modified with functionalized CFP (CFP-MDI) were subsequently fabricated by sedimentation to construct a “brick and mortar” structure. As a result, the comprehensive performance of laminated composites was effectively promoted by the introduction of CFP-MDI as a mortar. In particular, owing to the conspique synergistic effect between CFP and MDI, the interlaminar shear strength (ILSS) of the modified laminated composite increased by 17.93%, and the wear rate decreased by 38.18%, from 7.91×10⁻¹⁴ to 4.89×10⁻¹⁴ m³/(N·m), demonstrating the excellent ability of the modified composite to efficiently suppress crack and local damage propagation. This work provides a new strategy to achieve the integrated construction of toughening interlaminated and wear-resistant coatings, which is conducive to the large-scale application of laminated fabric composites in the friction transmission braking field.