A pH-response waterborne epoxy coating based on acid-alkali responsive supramolecular hydrogel

Based on supramolecular interaction, an acid-alkali response supramolecular gel with corrosion inhibitor loading of 50% was designed. By adding the gel to waterborne epoxy coating, a pH-response coating was obtained. The protonation and deprotonation of carboxyl and tertiary amine groups in the gel under different pH led to changes in the microstructure of the gel, which was confirmed by SEM and FTIR, thus controlling the release rate of corrosion inhibitor. After scratched coatings immersed in NaCl solution with pH = 5 for 70 h, the Rct of the coating with 1.5% supramolecular gel higher than that of the coating without gel, indicating the coating with supramolecular gel has good self-healing performance.