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

• Published in: Chemistry Africa Vol. 2; no. 2; pp. 277 - 289
• Main Authors: Nwanonenyi, S. C., Obasi, H. C., Chukwujike, I. C., Chidiebere, M. A., Oguzie, E. E.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2019
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Inorganic Chemistry; Organometallic Chemistry; Original Article; Soy polymer; Polyvinylpyrrolidone; Carbon steel; Corrosion
• ISSN: 2522-5758; 2522-5766
• DOI: 10.1007/s42250-018-00035-w

The inhibition of carbon steel corrosion induced in 1 M H 2 SO 4 by soy polymer (SP) from an extract of Glycine Mac-L and polyvinylpyrrolidone (PVP) respectively was investigated at 30–60 °C using hydrogen gas evolution, potentiodynamic polarization and quantum chemical computation technique respectively. Results obtained from hydrogen gas evolution technique revealed that SP and PVP respectively acted as an inhibitor for corrosion of carbon steel in 1 M H 2 SO 4 solution. The increase in inhibition efficiency (IE%) of SP and PVP reached a maximum at 89.5% and 84.36% respectively, and the increment was found to be dependent on inhibitor concentration. The combination of mixture of SP and PVP as single inhibitor showed better inhibition improvement compared to individual inhibitor. Temperature study reveals that inhibition efficiency decreased with a rise in temperature suggesting physical adsorption. The computed parameters for the activation energies and heat of adsorption of the corrosion process supported the physical adsorption mechanism proposed. Regression analysis (adsorption isotherm model) was used to approximate the adsorption characteristics of the SP and PVP. Polarization data revealed that SP and PVP respectively adsorption acted as a mixed type inhibitor and also affected the anodic and cathodic partial reactions process. Quantum chemical computations were performed using the density functional theory to establish a clear link existing between the effectiveness of the inhibitor and its electronic properties.