Anti-corrosion effect of morrocan flax seeds oil as an eco-friendly inhibitor on mild steel in acidic media

Abstract

This study targets Moroccan flax seeds oil valorization in corrosion inhibition. This oil is very rich in fat (41%) where unsaturated fatty acids represent the majority (87%). Physico-chemical analysis shows that flax seeds oil having a density of 0.931, a refractive index of 1.476, an acid index of 0.85 mg KOH/g oil, a saponification index of 192.11 mg KOH/g oil, a peroxide index of 1.03 meq O2/kg oil and an iodine index of 176.78 g/100 g oil. In this research, the effect of flax seeds oil on mild steel corrosion inhibition in 1 M HCl was analyzed using weight loss and impedance spectroscopy (EIS). From the results generated, optimum value (E%) of flax seeds oil was recorded as 94% and 92% at a concentration of 1 g/L by weight loss and EIS methods, respectively. Studies of impedance spectroscopy show that the inhibition mechanism is by the transfer of charges. The results also showed that the inhibitor flax seeds oil acts on the surface of the metal (mild steel) essentially by adsorption, leading to the formation of a protective film limiting the corrosion of mild steel.