Epoxy coating containing CoMOF@MBT metal-organic framework for active protection of aluminum alloy

A new cobalt-based metal-organic framework (CoMOF) was synthesized and subjected to comprehensive characterization employing a range of established techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal analyses. CoMOF was functionalized by loading mercaptobenzothiazole (MBT) onto CoMOF to fabricate CoMOF@MBT with anticorrosion properties. Polarization and immersion tests were employed to estimate the corrosion inhibition ability of CoMOF@MBT in NaCl medium. The results show that it inhibits corrosion of AA2024-T3 aluminum alloy when it is submerged in a NaCl solution with a pH of 3, yielding an inhibition efficiency of 87 %. Protective anticorrosion coatings were prepared by incorporating CoMOF@MBT particles into epoxy resin and coated on AA 2024-T3 substrate. Corrosion resistance of the protective coatings was assessed through the utilization of EIS and salt spray tests and the results show that scratched panels with coating containing CoMOF@MBT exhibit a slow decline in Rct values. It shows an Rct value of 1.45 × 104 Ω cm2 after 48 h of immersion in NaCl medium. The results demonstrated that incorporating CoMOF@MBT improves the capacity of epoxy coatings to withstand corrosion of AA2024-T3 panels in NaCl through the smart release of MBT molecules upon exposure to corrosive agents.