The anti-corrosion performance and catalytic passivation and sorptive corrosion inhibition self-healing of sulfonated aniline trimer modified basalt scale anti-corrosion coatings

Abstract

• Dispersion of basalt flakes (BS) was enhanced by sulfonated aniline trimer (SAT). • Hydrogen bonded SAT acted release in response to pH. • SAT catalyzed the formation of composite passive films on the surface of steel. • The multi-functional coordination endowed the coatings self-healing effect. Basalt flake (BS) was the new type of natural lamellar material with high strength and hardness, chemical inertia, acid and alkali resistance. It was expected to be the excellent anti-corrosion coating filler. The poor compatibility between BS and polymer resin limited its application. The modification of BS by sulfonated aniline trimer (SAT) was realized by covalent grafting and hydrogen bond adsorption. The structure and function of the materials were studied through spectrum and energy spectrum, electrochemical experiments, theory methods of quantum chemistry and molecular dynamics. The modification of SAT promoted the compatibility of BS and polymer. The stable dispersion of BS was attributed to covalent anchoring via SAT. This promoting effect was evaluated and confirmed by the shielding ability of coatings to corrosive media. Hydrogen bonded SAT behaved pH responsive release and catalytic passivation and corrosion inhibition on steel, and its release at coating defects endowed the self-healing effect. The mechanism was the formation of dense oxide films and SAT adsorption films.