Biomass-induced epoxy cross-linking leads to the restricted distribution of MXene to improve the tribological properties

To address the bottlenecks of conventional epoxy (EP) resin coatings, which arise from their reliance on toxic amine-based curing agents and high friction coefficients, this study develops green, self-lubricating EP-based coatings (named RLC@M-EP) based on the multiple active-site crosslinking mechanism of regenerated lignocellulose (RLC) and the lubrication enhancement of MXene. RLC is prepared from poplar powder using a deep eutectic solvent (DES), which provides abundant active hydroxyl groups that fully replace amine curing agents, crosslink with EP, and form a three-dimensional network. A series of RLC@M-EP coatings is fabricated by drop-casting while different mass fractions of MXene are introduced to enhance lubrication via interlayer shear and transfer film formation. The abundant active sites of RLC ensure efficient crosslinking with EP matrix, while MXene nanosheets delaminate and spread during friction to form a stable transfer film. Benefiting from the synergy between MXene's lubrication and the robust RLC-EP network strengthening effects, the RLC@M-EP coating achieves a minimum friction coefficient of 0.15 and significantly reduced wear. This work provides a new strategy for developing high-performance, eco-friendly, bio-based self-lubricating EP coatings by integrating chemical crosslinking with physical lubrication.