Protective Coatings Containing ZnMOF-BTA Metal–Organic Framework for Active Protection of AA2024-T3

Abstract

ZnMOF-BTA, a new metal–organic framework with excellent anti-corrosion properties was prepared and characterized. Polarization and immersion tests in 3.5 wt% NaCl were performed on AA2024-T3 alloy to assess the corrosion inhibition ability of ZnMOF-BTA. It showed an inhibition efficiency of more than 90%, indicating excellent corrosion inhibition of ZnMOF-BTA on AA 2024-T3 in NaCl. Moreover, ZnMOF-BTA particles were incorporated into polyurethane coatings to create corrosion-resistant coatings. Electrochemical tests and neutral salt spray analysis were used to assess the corrosion protection ability of ZnMOF-BTA-laden polyurethane coatings. The results of electrochemical impedance spectra clearly showed the outstanding corrosion resistance and durability of ZnMOF-BTA coatings after 1440 h of immersion with a high pore resistance (R_po) of 1.76 × 10¹⁰ Ω cm². In addition, during the cross-cut adhesion test, the coating did not detach from the substrate, and after the impact test, there was scarcely any indication of a fracture, which further supports the notion that the coating has strong adhesion to the substrate.