Protection of Mild Steel Corrosion in Sulphuric Acid Environment Using Wheat Starch

Abstract

The corrosion of mild steel in 0.5 M H2SO4acid solution and the inhibition process by wheat starch (WS) was investigated using weight loss and potentiodynamic polarization measurement techniques respectively. Gravimetric results revealed that there is significant reduction in the corrosion rate of mild steel in the presence of inhibited solution compared to blank solution, and also the inhibition efficiency was found to depend on the concentration of the WS. Data on potentiodynamic polarization results confirmed that WS exhibited mixed type inhibition behaviour, though the cathodic effect was more pronounced. The mode of WS adsorption on the corroding metal surface followed Langmuir isotherm model. In addition, the trend of inhibition efficiency with temperature, activation energy and heat of adsorption parameters revealed a strong interaction between the WS constituents and the corroding metal surface, thus indicating that WS lowered the corrosion process by blanketing the mild steel surface through chemical adsorption mechanism. The mechanism of inhibition was discussed in the light of the chemical structure of starch.

Tin corrosion inhibition by molybdate ions in 0.2 M maleic acid solution: Electrochemical and surface analytical study

“…To establish a complete, effective, and compact protective film, a suitable molybdate concentration is required. The efficiency of inhibitor in safeguarding or protecting metal surfaces during acid-induced corrosion is dependent on the ability of the molecular inhibitive species of the inhibitor to be adsorbed on the metal surface and the ability of the resulting adsorbed film to disengage the metal surface from the aggressive medium 29 .…”

Inhibition of Carbon Steel Corrosion in 1 M H2SO4 Using Soy Polymer and Polyvinylpyrrolidone

“…The adsorption isotherms (regression models) were used to study the inhibition adsorption process, that is, to determine the mode of inhibition adsorption for the corrosion reaction process. Also, it was done to present the importance of using regression models and its methodology in interpreting corrosion inhibition results [16][17][18][19]. Regression isotherm models used in the research include; Temkin, Freundlich and Langmuir adsorption isotherm.…”

“…The efficacy of inhibitor in safeguarding or protecting metal surfaces during acid induced corrosion is dependent on the ability of the molecular inhibitive species of the inhibitor to be adsorbed on the metal surface and the ability of the resulting adsorbed film to disengage the metal surface from the corrodent medium [17]. If it is believed that in inhibited solution corrosion occurs on the remaining free surfaces after some sites have been barricaded effectively by the adsorbed inhibitor film such that the covered surfaces have negligible rates of corrosion, the degree of surface coverage (θ) and inhibition efficiency (%I) can be computed according to the following Eqs.…”

“…The high rate of dissolution of carbon steel in 1 M H 2 SO 4 solution observed at elevated temperature could be attributed to more dissolution energy effect acquired by the corrosive agent within the aggressive medium. Also, the desorption of adsorbed inhibitor due to enhanced solution agitation by higher rates of hydrogen gas evolution at elevated temperature is possible and may cause the ability of the inhibitor to be adsorbed on the carbon steel surface to reduce [17]. In addition, this corrosion behaviour of carbon steel observed in 1 M H 2 SO 4 in the presence of SP and PVP respectively suggests physical adsorption of the SP and PVP on the corroding carbon steel surface [24].…”

Hydroxypropyl Cellulose as an Efficient Corrosion Inhibitor for Aluminium in Acidic Environments: Experimental and Theoretical Approach

“…Furthermore, studies on corrosion inhibition performance of polymers have shown that some polymers are quite useful in retarding the corrosion of metal surface in aggressive environments. Typical examples of the polymers that have been utilized as corrosion inhibitors for metal in various aggressive media include starch [8][9][10], carboxymethyl cellulose [11,12], chitosan [13], gum arabic [14] water-soluble polymers [15], a blend of polyvinylpyrrolidone and polyacrylamide [16], etc. Despite the significant contributions of some polymers as corrosion inhibitors for metals in various aggressive media, it is worthy to note that acid metal corrosion still exists and the effectiveness and durability of polymeric inhibitors vary with metals, corrodents, the condition of corrosion environment, etc.…”