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

The rapid dissipation of shear stress and frictional energy in the matrix of polymer-based self-lubricating composites can improve its friction-reduction and anti-wear performances. In this paper, regenerated lignocellulose (RLC) with a flexible architecture was used to assist ball-milling to exfoliate bulk molybdenum disulfide (MoS₂) and introduce them 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 have an additional reaction with the active hydrogen atoms or epoxy groups in the epoxy resin, improving the curing performance of the EP matrix and enhancing the flexibility and interfacial strength of the carbon fibers/epoxy composites. Due 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 reinforcement fibers more efficiently. The tensile strength and toughness of the final products were increased by 42.61% and 53.58%, the friction coefficient and wear rate were reduced by 34.78% and 30.77% over the RLC-EP composites. This approach of using RLC to assisted exfoliate MoS₂ nanosheets and building "flexible & rigid" transition framework in EP matrix provides a valuable reference for improving the interfacial strength and friction properties of polymer-based self-lubricating composites.