Palmitic acid-based amide as a corrosion inhibitor for mild steel in 1M HCl

Ali Kadhim Al-Edan; Wan Nor Roslam Wan Isahak; Zatil Amali Che Ramli; Waleed Khalid Al-Azzawi; Abdul Amir H Kadhum; Hazim Saad Jabbar; Ahmed Al-Amiery

doi:10.1016/j.heliyon.2023.e14657

Palmitic acid-based amide as a corrosion inhibitor for mild steel in 1M HCl

Heliyon. 2023 Mar 22;9(4):e14657. doi: 10.1016/j.heliyon.2023.e14657. eCollection 2023 Apr.

Authors

Ali Kadhim Al-Edan¹, Wan Nor Roslam Wan Isahak¹, Zatil Amali Che Ramli², Waleed Khalid Al-Azzawi³, Abdul Amir H Kadhum⁴, Hazim Saad Jabbar⁵, Ahmed Al-Amiery⁶

Affiliations

¹ Department of Chemical and Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Malaysia.
² Institute of Sustainable Energy, Universiti Tenaga Nasional (UNITEN), Kajang, 43000, Malaysia.
³ Al-Farahidi University, Baghdad, 10001, Iraq.
⁴ University of Al-Ameed, Iraq.
⁵ Department of Basic Sciences, College of Dentistry, University of Basrah, Iraq.
⁶ Universiti Kebangsaan Malaysia, National University of Malaysia, Bangi, Selangor, 43000, Malaysia.

Abstract

Due to growing environmental concerns and regulations limiting the use of harmful and toxic synthetic corrosion inhibitors, there is a high demand for sustainable corrosion inhibitors. In this study, a green and rapid technique was used to synthesize amide N-(4-aminobutyl)palmitamide (BAPA) which yielded 91.17% of the product within 2 min, compared to a low yield of 75-80% and a very long 8-10 h reaction time with the conventional thermal condensation method. The chemical structure of BAPA was analyzed by FT-IR, 1HNMR and 13CNMR spectra, as well as CHNS elemental analysis. When applied to mild steel exposed to 1 M HCl, BAPA delayed and reduced corrosion by adsorbing to the steel surface to form a protective layer. The inhibition efficiency increased with increasing amide concentration, and maximal inhibition of 91.5% was observed at 0.5 mM BAPA. The adsorption of BAPA on mild steel in an acidic solution was studied and inhibition performance was correlated with the calculated adsorption-free energy ΔGads, indicating good agreement between the experimental and adsorption findings. Surface morphology of untreated and treated mild steel coupons was evaluated by SEM, and based on density functional theory (DFT) computations and atomic charges analysis, a stronger interaction was observed between BAPA and mild steel surface leading to the formation of a compact protective film on the metallic surface. This protective film is attributed to the presence of nitrogen atoms and carbonyl group in the chemical structure of BAPA.

Keywords: Corrosion inhibitor; Diaminobutane 2; Microwave-assisted route 1; Palmitic acid 3.