Metal-organic frameworks/polydopamine synergistic interface enhancement of carbon fiber/phenolic composites for promoting mechanical and tribological performances.

Carbon fiber/phenolic composites have wide application prospects in the transmission of vehicles, where the combination of prominent mechanical and tribological properties is required. Multiscale metal-organic frameworks (MOFs) and polydopamine (PDA) as binary reinforcements were employed to construct a rigid-flexible hierarchical structure for improving the interfacial performances of friction materials. This unique rigid-flexible (MOFs/PDA) reinforcement could act as an effective interfacial linker, significantly facilitating the integration of fibers into the matrix and establishing a strong mechanical interlocking and chemical bonding onto the fiber/matrix interphase, thus boosting the mechanical and tribological properties of the composites. Benefiting from the MOF/PDA synergistic enhancement effects, the interlaminar shear strength of ZIF-8-composites (P1), MOF-5-composites (P2) and UiO-66-(COOH)-composites (P3) was improved by 70.80%, 43.80% and 53.28%, respectively. In addition, the wear rate of P1 decreased from 3.55 × 10 cm J to 2.45 × 10 cm J. This work provides a feasible approach for establishing rigid-flexible reinforced structures and opens up a double-component synergistic enhancement strategy to efficiently promote mechanical and tribological properties for fabricating high-performance carbon fiber/phenolic composites.