Enhancement of Anticorrosion Properties of Epoxy Based Primer Coating by Bis[[3,4-Dihydroxyphenylmethylene] carbonothioicdihydrazide] on AA2024-T3 Alloy

摘要

A corrosion inhibitor bis[[3,4-dihydroxyphenylmethylene]carbonothioicdihydrazide] (DCT) was synthesized and used to improve the corrosion resistance of an epoxy based primer coating on AA2024-T3 alloy in NaCl solution. The ability of DCT to inhibit the corrosion was evaluated by electrochemical studies. The compound exhibited an inhibition efficiency of 99%. The surfaces of the corroded specimens were characterized by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The anticorrosion nature of the substrate coated with a commercial epoxy-based primer doped with DCT was evaluated by electrochemical impedance spectroscopy and a salt spray test. The results established not only the ability of DCT to improve the anticorrosion property of the epoxy based primer coating on AA2024-T3 alloy but also a sustained corrosion protection (1000 h) of the alloy.