Flexible carbon fiber/epoxy resin-based self-lubricating composites reinforced by continuously regenerated lignocellulose and MoS₂ nanosheets

Rapid dissipation of shear stress and frictional energy in the matrix of polymer-based self-lubricating composites can improve their friction-reduction and anti-wear performance. In this work, regenerated lignocellulose (RLC) with a flexible architecture was used to assist ball-milling to exfoliate bulk molybdenum disulfide (MoS₂) and introduce it into an epoxy (EP) resin matrix to improve the mechanical and tribological properties of the final products. The abundant functional groups (hydroxyl and aldehyde groups) in RLC undergo an additional reaction with the active hydrogen atoms or epoxy groups in the EP resin, improving the curing performance of the EP matrix and enhancing the flexibility and interfacial strength of the carbon fiber/epoxy (CF/EP) composites. Owing to the simultaneous introduction of rigid MoS₂ nanosheets and flexible plant-fiber constructs in the EP matrix, external stresses can be transferred from the polymer matrix to the reinforcement fibers more efficiently. The tensile strength and toughness of the final products increased by 42.71% and 53.38%, respectively, and the friction coefficient and wear rate decreased by 37.50% and 30.77%, respectively, over those of the CFs/EP@RLC composites. This approach of using RLC to assist in exfoliating MoS₂ nanosheets and building a “flexible & rigid” transition framework in an EP matrix provides a valuable reference for improving the interfacial strength and friction properties of polymer-based self-lubricating composites.