Synthesis of 2-aminofluorene bis-Schiff base and corrosion inhibition performance for carbon steel in HCl

Three new bis-Schiff bases, including bis(2-aminofluorene)glyoxal(L1), bis(2-aminofluorene) p-phthalaldehyde (L2) and bis(2-aminofluorene) 4,4'-biphenyldicarboxaldehyde (L3), were synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR) and mass spectrometry (MS). Weight loss methods indicated that all these inhibitors have good resistance to 1.0 mol.L-1 hydrochloric acid corrosion, and the highest inhibition efficiency was 98.2% at 65 degrees C for L3. Polarization curves and electrochemical impedance spectroscopy (EIS) indicated that L3 exhibited excellent inhibition effect when concentration was 1.0 mmol.L-1. Moreover, the L3 was adsorbed spontaneously onto the surface by both physisorption and chemisorption, which followed the Langmuir adsorption isotherm. The relationship between molecular structure and quantum chemical structure parameters of three bis-Schiff base corrosion inhibitors was studied by Quantum chemistry calculation performed by density function theory (OFT) method. Results showed that L3 had excellent inhibition performance, which was consistent with experimental results. (C) 2018 Elsevier B.V. All rights reserved.

合成了三种新的双席夫碱，包括双（2 - 氨基芴）乙二醛（L1）、双（2 - 氨基芴）对苯二甲醛（L2）和双（2 - 氨基芴）4,4'-联苯二甲醛（L3），并通过傅里叶变换红外光谱（FT - IR）和质谱（MS）对其进行了表征。失重法表明，所有这些缓蚀剂对1.0 mol/L的盐酸腐蚀都有良好的抗性，L3在65℃时的缓蚀效率最高，可达98.2%。极化曲线和电化学阻抗谱（EIS）表明，当浓度为1.0 mmol/L时，L3表现出优异的缓蚀效果。此外，L3通过物理吸附和化学吸附自发地吸附在表面上，符合朗缪尔吸附等温式。通过密度泛函理论（DFT）方法进行量子化学计算，研究了三种双席夫碱缓蚀剂的分子结构与量子化学结构参数之间的关系。结果表明，L3具有优异的缓蚀性能，这与实验结果一致。（C）2018爱思唯尔有限公司。保留所有权利。