In view of the shortcomings of common inorganic corrosion inhibitors,such as slow chelating curing rate and poor compatibility between the formed inorganic rust chelationand organic coatings,the polydentate chelated hydrazone ligand(THL)was synthesized from 2-thiophene hydrazide and 1H-benzimidazole-2-formaldehyde. Its structure was characterized by infrared spectroscopy(ATR-FTIR),nuclear magnetic hydrogen spectroscopy(
1H NMR), ultraviolet spectroscopy(UV). THL was added to epoxy resin as an organiccorrosion inhibitor to prepare epoxy varnish. The corrosion resistance of varnish coatings withdifferent amount of THL was studied and analyzed by means of electrochemical impedancespectroscopy(EIS), salt spray resistance test,adhesion test,scanning electron microscope(SEM),and its corrosion prevention mechanism was preliminarily explored. The experimentalresults showed that the corrosion resistance of the varnish coating doped with THL wassignificantly better than that of the pure epoxy coating. When the amount of THL was 2%,the varnish coating had the best salt spray resistance and adhesion performance(16. 25 MPa),and the initial electrochemical impedance modulus could reach 6. 27×10
8 Ω·cm
2,after soaking in
3. 5%NaCl solution for 20 days,it was still as high as 1. 89×10
8 Ω ·cm
2,maintained at a high level. The doping of organic corrosion inhibitor(THL)could effectively improve the adhesion between the epoxy coating and the substrate,thereby improving the corrosion resistance of the coating.