Jamil Dalia M, Al-Okbi Ahmed K, Al-Baghdadi Shaimaa B, Al-Amiery Ahmed A, Kadhim Abdulhadi, Gaaz Tayser Sumer, Kadhum Abdul Amir H, Mohamad Abu Bakar
Chemistry Department, College of Science, University of Nahrain, Baghdad, Iraq.
University of Technology (UOT), Baghdad, 10001, Iraq.
Chem Cent J. 2018 Feb 5;12(1):7. doi: 10.1186/s13065-018-0376-7.
Relatively inexpensive, stable Schiff bases, namely 3-((4-hydroxybenzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ3) and 3-((4-(dimethylamino)benzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ4), were employed as highly efficient inhibitors of mild steel corrosion by corrosive acid.
The inhibition efficiencies were estimated based on weight loss method. Moreover, scanning electron microscopy was used to investigate the inhibition mechanism. The synthesized Schiff bases were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and micro-elemental analysis. The inhibition efficiency depends on three factors: the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight.
Inhibition efficiencies of 96 and 92% were achieved with BZ4 and BZ3, respectively, at the maximum tested concentration. Density functional theory calculations of BZ3 and BZ4 were performed to compare the effects of hydroxyl and N,N-dimethylamino substituents on the inhibition efficiency, providing insight for designing new molecular structures that exhibit enhanced inhibition efficiencies.
相对廉价且稳定的席夫碱，即3-((4-羟基亚苄基)氨基)-2-甲基喹唑啉-4(3H)-酮（BZ3）和3-((4-(二甲基氨基)亚苄基)氨基)-2-甲基喹唑啉-4(3H)-酮（BZ4），被用作腐蚀性酸对低碳钢腐蚀的高效抑制剂。
基于失重法估算了抑制效率。此外，使用扫描电子显微镜研究了抑制机理。通过傅里叶变换红外光谱、核磁共振光谱和微量元素分析对合成的席夫碱进行了表征。抑制效率取决于三个因素：抑制剂中的氮含量、抑制剂浓度和抑制剂分子量。
在最大测试浓度下，BZ4和BZ3的抑制效率分别达到了96%和92%。对BZ3和BZ4进行了密度泛函理论计算，以比较羟基和N,N-二甲基氨基取代基对抑制效率的影响，并为设计具有更高抑制效率的新分子结构提供思路。
