Self-healing polyurethane anticorrosive coatings based on alkyd resin microcapsules

In this paper, self-healing microcapsules were prepared by in situ polymerization using poly(vinyl alcohol) as the emulsifier, urea-formaldehyde resin as the shell material, and alkyd resin as the core material. The average diameter of the obtained microcapsules was about 20 μm and the encapsulation rate of alkyd resin was 50.7 wt.%. The self-healing coating was prepared by adding 5 wt.% of microcapsules to the pure polyurethane coating and then coated on AA2024-T3 substrate. The self-healing effect was evaluated by scanning electron microscopy. Electrochemical impedance spectroscopy tests and neutral salt spray tests confirmed that the self-healing coating had good anticorrosion properties.