Preparation of polyaniline encapsulated acrylic resin microcapsules and its active corrosion protection of coating for magnesium alloy

Herein, novel microcapsules were designed and synthesized by emulsion polymerization and used for self-healing coating for magnesium alloy. Polyaniline (PANI) was used directly as a capsule shell, and thermoplastic acrylic resin was used as the core material. Polymerization processes of microcapsules were observed by optical microscopy, and some key polymerization parameters were discussed. Composite microcapsules were analyzed by scanning electron microscopy, infrared spectroscopy, and thermogravimetric analysis. The corrosion protection performance of microcapsule and epoxy varnish coatings with defect was tested by electrochemical impedance spectroscopy. Results showed that the microcapsule coating had a higher corrosion protection than epoxy varnish coating because capsule core acrylic resin could significantly improve the shield performance of the defect coating and capsule shell PANI could inhibit the corrosion reaction of magnesium alloy.