Simultaneous Self‐Healing and Corrosion Protection Using Disulfide Bonds

Abstract Protective coatings on metallic structures display barrier properties to hinder their deterioration by corrosion and hereby prolonging their lifetime. Herein, a polymer with self‐healing and anticorrosion properties is synthesized to prepare coatings on steel substrates. First, a monomer based on the 2‐mercaptobenzothiazole chemical structure is synthesized as a suitable monomer for a polyaddition reaction to form polyurethane with the inhibitor as a side chain linked by a disulfide bond. This design endows coatings with self‐healing properties triggered by disulfide exchange reactions and anticorrosion properties due to corrosion‐responsive release of the inhibitor. Thus, the corrosion rate of steel substrates coated with polymer‐corrosion inhibitor conjugate is ≈32 times lower than for steel substrates coated with an analog self‐healing polymer without conjugated corrosion inhibitor. The healing efficiency of anticorrosion and mechanical properties is exceeding 93% and 96%, respectively.