One-Step Synthesis of Functionalized Microcapsules with Excellent Dispersibility for Efficient Self-Healing and Anticorrosion Coatings

The practical application of self-healing coatings relies on the uniform dispersion of microcapsules within the coating matrix. In this study, a novel approach was employed to synthesize microcapsules that were functionalized with hydroxyl, amino, and epoxy groups through a combination of intraemulsion droplet phase separation and photopolymerization. Microcapsule formation and shell modification were achieved in a one-pot process, which proved to be more efficient and simpler compared to other established synthesis methods. The effects of functional groups (hydroxyl, amino, and epoxy groups) and modification degrees on the dispersibility of microcapsules and the coating properties were investigated. The results showed that the epoxy-modified microcapsules possessed the best dispersibility in the UV-cured coating matrix among the three functionalized microcapsules, and the dispersibility of the microcapsules became better with the increase of the epoxy-modified degree. The improved dispersibility of microcapsules led to a significant improvement in the self-healing and anticorrosion properties of the coatings. The pure coating showed significant corrosion after only 4 days of salt spray testing, while the coating with MC-Ep showed no corrosion after 20 days of salt spray testing. Furthermore, the prepared coatings demonstrated reliable and effective self-healing properties, which could significantly extend the coatings' service life. This study provides a novel, efficient, and feasible strategy for the synthesis of functionalized microcapsules and their incorporation into coatings. The findings offer valuable insights into the development of advanced self-healing and anticorrosive coatings that hold great promise for various industrial applications.