Preparation of epoxy microcapsule based self-healing coatings and their behavior

In this paper, epoxy microcapsules were prepared by interfacial polymerization of epoxy resin droplets with ethylenediamine (EDA), and the capsules were characterized by scanning electron microscope (SEM). Then, the coatings containing epoxy microcapsules were applied on carbon steels, and their behavior and self-healing effect were investigated by electrochemical impedance spectroscopy (EIS) technique and SEM observation. The experimental results demonstrate that the artificial scratches were successfully healed in about 4-h after made. Furthermore, coating prepared from 20wt.% epoxy microcapsules shows the best performance among all the prepared coatings. ► Developed encapsulation process based on interfacial polymerization. ► Microcapsule with ethylenediamine-epoxy shell, a new shell material. ► Effective self-healing coating, with the scratches healed in about 4-h.