Al-Edan Ali Kadhim, Roslam Wan Isahak Wan Nor, Che Ramli Zatil Amali, Al-Azzawi Waleed Khalid, Kadhum Abdul Amir H, Jabbar Hazim Saad, Al-Amiery Ahmed
Department of Chemical and Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Malaysia.
Institute of Sustainable Energy, Universiti Tenaga Nasional (UNITEN), Kajang, 43000, Malaysia.
Heliyon. 2023 Mar 22;9(4):e14657. doi: 10.1016/j.heliyon.2023.e14657. eCollection 2023 Apr.
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 -(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.
由于对环境的担忧日益增加以及限制使用有害和有毒合成缓蚀剂的法规出台，对可持续缓蚀剂的需求很高。在本研究中，采用了一种绿色快速技术合成酰胺-（4-氨基丁基）棕榈酰胺（BAPA），该技术在2分钟内产率达到91.17%，相比之下，传统热缩合方法产率低至75-80%，且反应时间长达8-10小时。通过傅里叶变换红外光谱（FT-IR）、核磁共振氢谱（1HNMR）、核磁共振碳谱（13CNMR）以及元素分析（CHNS）对BAPA的化学结构进行了分析。当应用于暴露在1M盐酸中的低碳钢时，BAPA通过吸附在钢表面形成保护层来延缓和减少腐蚀。缓蚀效率随着酰胺浓度的增加而提高，在0.5mM BAPA时观察到最大缓蚀率为91.5%。研究了BAPA在酸性溶液中对低碳钢的吸附，并将缓蚀性能与计算得到的吸附自由能ΔGads相关联，表明实验结果与吸附结果吻合良好。通过扫描电子显微镜（SEM）评估了未处理和处理后的低碳钢试片的表面形貌，基于密度泛函理论（DFT）计算和原子电荷分析，观察到BAPA与低碳钢表面之间有更强的相互作用，导致在金属表面形成致密的保护膜。这种保护膜归因于BAPA化学结构中氮原子和羰基的存在。
