Alhaffar Mouheddin T, Umoren Saviour A, Obot Ime B, Ali Shaikh A
Department of Chemistry, Faculty of Science, King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia.
Centre for Research Excellence in Corrosion, Research Institute, King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia
RSC Adv. 2018 Jan 8;8(4):1764-1777. doi: 10.1039/c7ra11549k. eCollection 2018 Jan 5.
Two isoxazolidine derivatives namely 5-(benzo[][1,3]dioxol-5-ylmethyl)-2-tetradecyl isoxazolidine (BDMTI) and 5-(4-hydroxy-3-methoxybenzyl)-2-tetradecyl isoxazolidine (HMBTI) were synthesized and characterized using FTIR, C-NMR, H-NMR, and elemental analysis. The synthesized compounds were evaluated as corrosion inhibitors for API 5L X60 steel in 1 M HCl in the temperature range of 25-60 °C using gravimetric and electrochemical (Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarization (PDP) and Linear Polarization Resistance (LPR)) techniques. The effect of addition of a small amount of iodide ions on the corrosion inhibition performance of the compounds was also assessed. In addition, quantum chemical calculations and Monte Carlo simulations were employed to correlate the electronic properties of the compounds with the corrosion inhibition effect as well as to evaluate the adsorption/binding of the inhibitor molecules on the steel surface. Experimental results show that the two compounds inhibited the corrosion of carbon steel in an acid environment with HMBTI showing superior performance. The corrosion inhibition effect was found to be dependent on the inhibitors' concentration and temperature. Addition of iodide ions improves the inhibition efficiency considerably due to co-adsorption of the iodide ions and the inhibitors on the steel surface which was competitive in nature as confirmed from the synergistic parameter ( ) which was less than unity at higher temperature. Experimental and theoretical results are in good agreement.
合成了两种异恶唑烷衍生物，即5-(苯并[][1,3]二氧杂环戊烯-5-基甲基)-2-十四烷基异恶唑烷(BDMTI)和5-(4-羟基-3-甲氧基苄基)-2-十四烷基异恶唑烷(HMBTI)，并通过傅里叶变换红外光谱(FTIR)、碳核磁共振谱(C-NMR)、氢核磁共振谱(H-NMR)和元素分析对其进行了表征。采用重量法和电化学方法(电化学阻抗谱(EIS)、动电位极化(PDP)和线性极化电阻(LPR))，在25-60℃温度范围内，对合成的化合物作为API 5L X60钢在1 M盐酸中的缓蚀剂进行了评价。还评估了添加少量碘离子对化合物缓蚀性能的影响。此外，采用量子化学计算和蒙特卡罗模拟方法，将化合物的电子性质与缓蚀效果相关联，并评估缓蚀剂分子在钢表面的吸附/结合情况。实验结果表明，这两种化合物在酸性环境中均能抑制碳钢的腐蚀，其中HMBTI表现出优异的性能。发现缓蚀效果取决于缓蚀剂的浓度和温度。碘离子的加入显著提高了缓蚀效率，这是由于碘离子和缓蚀剂在钢表面的共吸附作用，从协同参数()可以证实，在较高温度下，这种共吸附作用具有竞争性，协同参数小于1。实验结果与理论结果吻合良好。
