Corrosion Inhibition of Mild Steel and Aluminum in Hydrochloric Acid Solutions by Gum Exudates from Erythrophleum Africanum

¹Department of Chemistry, Faculty of Science, Nigerian Defence Academy, Kaduna, Nigeria

²Department of Chemistry, Nigeria Police Academy, Wudil Kano State, Nigeria

*Corresponding Author: Paul Ocheje Ameh, Department of Chemistry, Faculty of Science, Nigerian Defence Academy, Kaduna, Nigeria; Email: [email protected]

Received Date: March 31, 2023

Publication Date: April 24, 2023

Citation: Clement AS. (2023). Corrosion Inhibition of Mild Steel and Aluminum in Hydrochloric Acid Solutions by Gum Exudates from Erythrophleum Africanum. Catalysis Research. 3(1):10.

Copyright: Clement AS. © (2023).

ABSTRACT

The corrosion inhibition potentials of gum exudates extracted from Erthrophleum Africanum on mild steel and aluminium in acidic media were studied using gravimetric, Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) and potentiodynamic methods. The results range for gravimetric showed (30.30-80.0 %) and potentiodynamic polarization (66.50-86.74 %) which shows that the inhibition efficiency of the inhibitor increases with increase in concentration of gum exudate but decreases with increasing temperature. The addition of the gum exudate affects both the cathodic and anodic partial reaction, thereby reducing the cathodic and anodic current densities and the corresponding corrosion densities, which makes the gum act as a mixed type of inhibitor. The inhibitor was found to be an adsorption inhibitor that best fits the Temkim adsorption model; because the data have high degrees of linearity and the parameters were positive. The activation energy values ranges from 10 - 20 J/mol which indicates that the adsorption of the inhibitors favors the mechanism of physical adsorption, free energy of absorption ranges from -10.51 to -11.69 J/mol which indicate that the reaction is spontaneous and it’s an exothermic reaction. FTIR spectra of the inhibitors and the corrosion products of mild steel and Aluminum (in the presence of the inhibitors) revealed that there were shifts in frequencies of adsorption (821,925,1620,1730,1990) suggesting that some functional groups were used in adsorption and some new bonds were formed. (CH Rocking, = CH ‘oop’, C=O symmetric stretch) Examinations of the morphology of the mild steel and Aluminum (using SEM) before and after inhibition revealed the formation of protective coverage over the surface of the metal

Keywords: Corrosion inhibition, Adsorption isotherm, Erthrophleum africanum, Natural polymers