Smart Coating Based on Urea-Formaldehyde Microcapsules Loaded with Benzotriazole for Corrosion Protection of Mild Steel in 3.5 % NaCl

Urea-formaldehyde (UF) microcapsules loaded with linseed oil (LO) and benzotriazole (BTA) as core materials have been synthesized by in situ emulsion polymerization. The capsules were characterized by FTIR spectroscopy and particle size analysis. Surface morphology of the microcapsules was analyzed using scanning electron microscopy (SEM). The microcapsules were incorporated into epoxy resin and coated on a mild steel substrate to form a corrosion resistant organic coating. The self-healing property of coatings loaded with different weight % of microcapsules containing LO + BTA was tested by immersion of the UF coated mild steel specimens in 3.5 wt % NaCl solution. It was analyzed through visual inspection, weight loss measurements, and SEM of the scribed region of coating. It was observed that the addition of microcapsules enhances the corrosion resistance of the scratched samples.