Self‐lubricating epoxy composite coating with linseed oil microcapsule self‐healing functionality

Abstract

Cured epoxy resins have poor abrasion resistance, which shortens the service life of the material. This work aims to improve the tribological properties of epoxy resins by coupling self‐lubrication and auto‐healing. In this study, linseed oil microcapsules with an average particle size of 38.57 μm and good thermal stability were successfully prepared by in situ polymerization. The effects of microcapsule content on the tribological, mechanical, and self‐healing properties of the composite coatings were studied. It was demonstrated that the composite coating has outstanding self‐lubricating properties. The coefficient of friction reduced from 0.634 (pure epoxy resin) to 0.0459 (epoxy resin with 10 wt.% linseed oil microcapsules). Wear rate reduced from 7.16 × 10−4 mm3/(N m) to 1.74 × 10−5 mm3/(N m). The self‐lubricating mechanism of the coating was investigated by SEM and EDS, which indicated that the formation of uniform and continuous lubricating film on the surface of the friction pairs was the key to improving the wear resistance of the material. In addition, the linseed oil released after the microcapsules rupture can repair the abrasion marks by reacting with oxygen during the friction process. The dual‐functional effect of linseed oil microcapsules prolongs the life of epoxy resin coating and expands its application range.