Insight into mitigation of corrosion behavior of novel chalcone derivative for AZ91 Mg alloy in saline solution: synthesis, characterization, electrochemical and adsorption studies

Abstract

Magnesium is the lightest structural metallic element, and exhibited an important developmental potential due to the growing need for lightweight electronics and transportation (aerospace, automobile, etc.). A novel chalcone derivative 4-(3-(4-(4-((4-(4-(3-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acryloyl)-5-methyl-1H-1,2,3-triazol-1-yl)phenyl)sulfonyl)phenyl)-5-methyl-1H 1,2,3-triazol-1-yl)-3-oxoprop-1-en-1-yl)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (DMPO) was synthesized. The chemical structure of the newly synthesized DMPO was inferred from its spectral data (H1-NMR, C13-NMR, and FT-IR). Its structure was also affirmed by field emission scanning electron microscopy-energy dispersive X-ray (SEM-EDX), and thermal stability was studied by thermal gravimetric analysis (TGA-DTA). Then, its potency as a remarkable corrosion inhibition for AZ91 magnesium alloys in NaCl (3.5 wt%) solution was studied. Hydrogen evolution, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) investigations were utilized to assess the impact of the newly synthesized chalcone derivative DMPO on the electrochemical performance of AZ91 Mg alloy in NaCl solution (3.5 wt%). SEM-EDX was used to evaluate the surface and elemental analysis of an AZ91 Mg alloy immersed in NaCl solution (3.5 wt%) with and without DMPO inhibitor. The obtained electrochemical evaluation revealed that DMPO functions as a high-performance, environmentally friendly AZ91 Mg alloy inhibitor in NaCl (3.5%) recording inhibition efficiency 93.7% at 100 ppm. Potentiodynamic polarization experiments revealed that the corrosion was inhibited due to the adsorption of inhibited molecules which follows the Langmuir adsorptive process. The findings also affirmed the development of protective film on Mg alloy surface. In electrochemical tests, it was discovered that DMPO molecules were mixed-type corrosion inhibitors.