Renewable Polyurethane Microcapsules with Isosorbide Derivatives for Self-Healing Anticorrosion Coatings

Renewable polyurethane microcapsules containing isosorbide derivatives for self-repairing anticorrosion coatings were easily manufactured by interfacial polymerization of a dimer ester–diisocyanate (DE–TDI) prepolymer derived from waste vegetable oil and 1,4-butanediol (BD) as a chain extender using ultrasonication. Two kinds of corrosion inhibitors were also synthesized by the ring-opening reaction of succinic anhydride (SA) or maleic anhydride (MA). Microcapsules having 11–38 μm in diameter were obtained, and the typical core content of microcapsules was around 40–45 wt %. Salt spray tests used for evaluating self-healing anticorrosion coating systems showed significant rust retardancy, depending on the content of the isosorbide derivatives for corrosion control.