Oil-containing microcapsule-triggered lubrication enables ultra-low friction and high wear resistance in phenolic epoxy coating

Oil-containing self-lubricating composite material is an effective approach to address the wear issues of polymer materials. In this work, the traditional lubricant 500SN was encapsulated within melamine-formaldehyde (MF) resin shells through in-situ polymerization to prepare 500SN@MF microcapsules. Comprehensive characterizations confirmed that the 500SN@MF microcapsules have a well-defined spherical morphology, improved thermal stability, and excellent compatibility with phenolic epoxy resin. The 500SN@MF microcapsules were mixed with phenolic epoxy and cured at room temperature to form a composite self-lubricating coating. Tribological performance tests demonstrated that the composite coating exhibited exceptional anti-wear and friction-reducing properties, with a friction coefficient (COF) of ~0.038 and a notably low wear rate of 0.077×10⁻⁶ mm³/(N·m) under 5 N load and 20000 friction cycles. Significantly, the 500SN@MF microcapsules could be produced in small batches while maintaining an intact core-shell structure, which offers a scalable material solution for achieving efficient, long-term lubrication in mechanical components and significantly extending their service life.