New Formulation based on Ceratonia Siliqua L Seed Oil, as a Green Corrosion Inhibitor of Iron in Acidic Medium

In this study, the effect of the formulation derived from Ceratonia siliqua L, (noted FCSL) as green corrosion inhibitor of iron in solution simulated to the rain water (at pH=3.6) was examined by using the weight loss, the potentiodynamic polarization and the electrochemical impedance spectroscopy measurements. In addition, determination of the physico-chemical indexes of the seeds oil of Ceratonia siliqua L, showed that it is a long chain unsaturated oil. The results indicated that the inhibition efficiency (% IE) of the FCSL formulation increased with increasing both inhibitor concentrations and immersion time. The inhibition efficiency reached a value of 98.6% at 750 ppm of the FCSL formulation. This formulation may be form a filmed and acts as a barrier, which minimize the contact area between metallic surface and corrosive solution. This leads to decrease the oxidation of the iron substrate. The metallic surface, after inhibitor treatment has been observed using SEM coupled with the EDX analysis. The obtained results indicate that the FCSL acts as an excellent mixed-type inhibitor.