A polyurethane coating using CoMOF-BTA metal-organic framework for active protection of AA2024-T3

CoMOF-BTA, a new metal-organic framework with inherent corrosion inhibition ability was prepared via a one-step solvothermal process and characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and thermal analyses. Immersion and polarization tests were conducted to evaluate the ability of CoMOF-BTA to resist corrosion on AA2024-T3 alloy in NaCl solution. In addition, CoMOF-BTA particles were incorporated into polyurethane coatings to produce active anti-corrosion coatings, whose corrosion protection capabilities were assessed using electrochemical methods and salt spray analysis. The impedance results show that polyurethane coatings containing CoMOF-BTA have coating resistances (Rcoat) that are around two orders of magnitude higher than that without the CoMOF-BTA particles. The salt spray analysis also indicates the corrosion protection ability of coatings containing CoMOF-BTA particles after a long period of exposure. The results demonstrate that CoMOF-BTA improved the ability of AA2024-T3 to resist corrosion and confirm the anti-corrosion properties of CoMOF-BTA-laden coatings by the controlled release of BTA molecules in NaCl solution. This study offers a new anti-corrosion MOF material and active coating for the protection of aluminum alloys against corrosion.