Renewable polyurethane microcapsules based on a dimer-acid-based polyol were prepared through interfacial polymerization with a homogenizer and sonicator. The dimer-acid-based polyol was used to produce a dimer ester-toluene diisocyanate prepolymer by reacting with toluene 2,4-diisocyanate (TDI). Then, the dimer ester-toluene diisocyanate prepolymer was reacted with 1,4-butanediol (BD) in order to form the shell of the microcapsules, which contained triazole- and oleate-derivative corrosion inhibitors as core materials for anticorrosion effects in coating systems. The resultant microcapsules using a homogenizer (DTM) and a sonicator (DSM) consisted of the anticorrosion agent core and renewable polyurethane shell, and were prepared under controlled optimum conditions (2000–8000 rpm, 500 W). Specific core contents were approximately 47–58%, and the ratios of the shell thicknesses to the capsule diameters were approximately 0.08. The anticorrosion properties of the self-healing coatings based on smart microcapsules were investigated on scratched panels using the salt spray test. The scratch test revealed that the self-healing coating system had significant ability to prevent corrosion growth. Anticorrosion coating surfaces with functionalized smart microcapsules did not corrode so notably that the corrosion-resistance effect, as the rusting degree, was attenuated by the salt spray, and the rusting degree of the self-healing microcapsules increased to 0.045% of the panel area.
Volume 109, August 2017, Pages 61–69