Mathematical Modeling of Corrosion Inhibition Efficiency of Acalypha Wilkesiana Leaves

International Journal of Research and Scientific Innovation (IJRSI) | Volume VI, Issue V, May 2019 | ISSN 2321–2705

Mathematical Modeling of Corrosion Inhibition Efficiency of Acalypha Wilkesiana Leaves

Fehintola¹ E. O, Olasehinde², E.F, Lajide², L and Oloruntoba³, D.T

¹Department of Chemistry, Adeyemi Federal University of Education, Ondo, Nigeria
²Department of Chemistry, Federal University of Technology, Akure, Nigeria
³Department of Metallurgical and Materials Engineering, Federal University of Technology, Akure, Nigeria

Abstract:-Acalypha wilkesiana leaves were collected at Adeyemi College of Education, Ondo. Cleaned leaves were subjected to sun-dry and air-dry processes. Sun-dried and air-dried leaves were powdered, sieved and stored in desiccators at room temperature. A known mass of the powdered leaves was soaked in ethanol in different containers for 72 hours to obtain inhibitor extracts. Extracts were used as inhibitor for mild steel of known composition. Weight loss, inhibition efficiency (IE) and corrosion rate were studied using standard methods. Models that relate concentration of inhibitor and temperature to IE were proposed, established and evaluated using statistical methods . The inhibition efficiency increases with increasing extracts concentration to 88.89 % and 80.51 % at 333K of 1.0 g/l of extracts for the air and sun-dried extracts, respectively. The inhibition efficiency also increases with increasing temperature of the reaction system suggesting a chemical adsorption mechanism. The best models for sun and air dried extracts were IE= -31.71+7.07X₁+0.25X₂+0.09X₁X₂  and IE= 0.21X_1^0.23 X_{2 ^1.04} with MSC (4.3 and 4.1), AIC (69.3 and 67.9) and SC (72.3 and 70.8) and CD (0.990 and 0.988), respectively. The worst models for sun and air dried extracts were Log(IE)=1.91+0.27 Log(X₁)+0.0002 Log(X₂)+ 0.0007 Log(X₁X₂) and Log(IE)=1.92+0.26 Log(X₁)+0.002 Log(X₂) with MSC (1.7 and 2.1) , AIC (120.4 and 111.6) , SC (123.4 and 108.6) and CD ( 0.887 and 0.910) respectively. It was concluded that these two extracts of the present study can serve as effective green corrosion inhibitors for mild steel in acidic media.

Keywords: Inhibition efficiency, weight loss measurement, Corrosion, Plant extracts, Mild steel, Statistical analysis.

I. INTRODUCTION

Iron and its alloys are widely used in engineering works such as constructions of overhead tanks, general and petroleum refineries equipment, pipes and valves. The main setback of using iron and alloys of iron is its aggressive reactions in acidic media. Acid media are generally used in the removal of unwanted scale and rust on iron and its alloys in many industrial processes (Anees et al., 2018).

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