Preparation and application of benzotriazole-loaded CaSiO₃ in epoxy coatings with corrosion resistance

This study presents a epoxy coating system using CaSiO₃ particles loaded with benzotriazole (BTA) as a corrosion inhibitor. BTA adsorption onto porous CaSiO₃ was confirmed by FTIR and XRD, indicating physical interaction without structural disruption. SEM revealed improved surface morphology and filler dispersion. BTA release from CaSiO₃-BTA was pH-responsive, accelerating in acidic and alkaline media, and followed Korsmeyer–Peppas and Higuchi kinetic models. Mechanical testing showed that incorporating CaSiO₃ and CaSiO₃-BTA enhanced hardness and abrasion resistance without affecting adhesion. Electrochemical impedance spectroscopy indicated that epoxy/CaSiO₃-BTA coatings offered improved long-term corrosion protection in NaCl solution, owing to triggered BTA release and the formation of a protective film. These results demonstrate the potential of CaSiO₃-BTA as a multifunctional additive that reinforces mechanical strength and enables self-healing corrosion resistance in epoxy coatings.