Experimental and theoretical studies on inhibition of Quinoxaline derivatives against corrosion of mild steel in acidic medium

The inhibitory effect of 1,4-diallyl-6-methylquinoxaline-2,3(1h,4h)-dione (2) on the corrosion of mild steel in 1 m hydrochloric acid was studied using mass loss,potentiodynamic polarization technique and electrochemical impedance spectroscopy measurements at 308k. the investigation results indicate that the quinoxaline derivative with an average efficiency of 86% at 10-3m of additive concentration have fairly effective inhibiting properties for mild steel in hydrochloric acid,and acts as cathodic type inhibitor character. the inhibition efficiencies measured by all measurements show that the inhibition efficiencies increase with increase in inhibitor concentration. this reveals that the inhibitive mechanism of inhibitors was primarily due to adsorption on mild steel surface,and followed langmuir adsorption isotherm. moreover,to provide further insight into the mechanism of inhibition,quantum chemical calculations of the inhibitor were performed. © 2017,university of mohammed premier oujda morocco.