新型离子液体的合成及其阳离子基团缓蚀性能

以高纯环烷酸为原料,合成了一系列含咪唑啉环的新型离子液体Ⅰ～Ⅴ,探讨了阳离子咪唑啉基团中N_（3）原子上取代基与缓蚀性能的关系.采用碳钢挂片失重法和电化学测试法,评价了它们在酸性溶液中的缓蚀性能;采用量子化学法和极化效应指数法,分别计算了离子液体Ⅰ～Ⅴ阳离子咪唑啉基团的前线轨道能量及其相应的PEI等参数.实验结果和理论分析表明：离子液体Ⅰ～Ⅴ阳离子咪唑啉基团的缓蚀效率呈现如下关系,Ⅴ＞Ⅳ＞Ⅲ＞Ⅱ＞Ⅰ;其缓蚀效率与E_HOMO、ΔE_L-H和PEI等参数间均具有良好的线性关系.     

水溶性咪唑啉酰胺的合成及其性能研究

按照四乙烯五胺∶壬酸∶冰乙酸的摩尔比为1∶1∶4.5进行反应物料配制,以甲苯为携水剂,通过端基酰胺化脱水反应、乙酰胺化脱水反应和环化脱水反应,最终制备合成了水溶性咪唑啉酰胺。依据国标方法对水溶性咪唑啉酰胺在不同质量分数下进行水溶性测试研究。结果表明,制备合成的水溶性咪唑啉酰胺具有良好的水溶性。利用GaussView 6可视化软件对水溶性咪唑啉酰胺分子进行结构优化,获得了最高占据分子轨道HOMO和最低未占分子轨道LUMO能量分布图,通过Gaussian 16软件的量化模拟计算分析,得到了最高占据轨道能量(E_HOMO)和最低未占轨道能量(E_LUMO),根据前线轨道理论,揭示了水溶性咪唑啉酰胺的缓蚀性能。同时,利用失重法对水溶性咪唑啉酰胺的缓蚀性能进行研究,并根据扫描电镜(SEM)形貌分析,进一步证明了合成的水溶性咪唑啉酰胺具有良好的缓蚀效果。     

席夫碱基咪唑啉缓蚀剂的密度泛函理论研究

用量子化学密度泛函理论(DFT)中的B3LYP方法,在6-31G(d)和6-311G(d,P)基组水平上,研究了席夫碱基咪唑啉化合物BIA、BIOHA、BIMHA和BIMMA的缓蚀性能与分子结构及电子结构的关系,讨论了计算结果与缓蚀性能的关系。结果表明缓蚀性能与电负性χ、亲电指数ω等亲电反应参数相关性良好,最后用Fukui指数分析了分子中原子的反应性。可以认为缓蚀剂分子通过离域于苯环平面LUMO接受电子发生亲电作用与金属表面形成吸附膜。     

咪唑啉及其衍生物的缓蚀作用

概述了咪唑啉型缓蚀剂研究的发展和缓蚀剂缓蚀机理研究方法的发展,重点讨论了咪唑啉及其衍生物的结构特点、缓蚀作用的电化学特征、在金属表面的吸附特征、咪唑啉及其衍生物的分子结构与其缓蚀作用的关系,探讨了查明咪唑啉及其衍生物的缓蚀机理对设计新型的缓蚀剂分子,进一步开发高效低毒的缓蚀剂品种的意义.     

吗啉衍生物抑制CO2腐蚀性能的研究

用静态失重法研究了吗啉衍生物及其复配物对CO2腐蚀的缓蚀效果。试验表明，该吗啉衍生物与咪唑啉衍生物、硫脲及丙炔醇复配后对抑制CO2的腐蚀有良好的效果，气相中的缓蚀效率可达93．6％，液相中的缓蚀效率为96．9％。     

咪唑啉类缓蚀剂的研究现状及展望

介绍了咪唑啉类缓蚀剂的制备,研究了影响产物收率的几个主要因素并比较了不同咪唑啉衍生物的缓蚀性能,阐述了其缓蚀机理,最后介绍了咪唑啉类缓蚀剂的应用现状及前景。     

吗啉衍生物抑制CO_2腐蚀性能的研究

用静态失重法研究了吗啉衍生物及其复配物对CO2腐蚀的缓蚀效果。试验表明,该吗啉衍生物与咪唑啉衍生物、硫脲及丙炔醇复配后对抑制CO2的腐蚀有良好的效果,气相中的缓蚀效率可达93.6%,液相中的缓蚀效率为96.9%。     

环烷基咪唑啉衍生物在硫酸介质中的缓蚀性能研究

介绍了环烷基咪唑啉衍生物(NID)的合成,并探讨了其在硫酸介质中的缓蚀性。结果表明,在5%H2SO4溶液中,在50℃,投加剂量为0.1%时,合成的环烷基咪唑啉衍生物对碳钢片缓蚀率达93%以上。因此,所合成的环烷基咪唑啉衍生物是一种优异高效的酸洗缓蚀剂。     

吗啉类缓蚀剂的合成及其应用研究

以吗啉、二正丁胺、三聚甲醛等为原料合成了一种新型的吗啉衍生物,并将该吗啉衍生物与其它物质进行复配,并用静态失重法,研究了吗啉衍生物及其复配物对CO2腐蚀的缓蚀效果试验表明,该吗啉衍生物与咪唑啉衍生物、硫脲及丙炔醇复配后对抑制CO2的腐蚀有良好的效果,气相中的缓蚀效率可达93.6%,液相中的缓蚀效率为96.9%.     

咪唑啉类缓蚀剂性能的评价及其机理研究

针对陕北某天然气气井腐蚀现象日益严重以及天然气中H2S,CO2等酸性组分质量浓度不断增大等一系列亟待解决的生产实际问题,首先利用质量损失法对4种常用的咪唑啉类缓蚀剂进行了缓蚀效果评价,然后通过量子化学计算和分子动力学模拟的方法对其缓蚀行为和作用机理进行了初步研究。结果表明:咪唑啉类缓蚀剂对金属的缓蚀作用,主要由于其分子中的咪唑环及极性基团的作用;发生吸附时,咪唑环优先吸附于金属表面,有利于咪唑啉分子在金属表面形成稳定的保护膜。同时憎水支链的自由移动与伸展,能够在远离金属表面的地方形成一层致密的疏水层,阻碍了腐蚀介质与金属基体的接触,有效地增强了咪唑啉分子的缓蚀效果。缓蚀剂缓蚀性能的理论评价结果与实验结果相吻合。     

Quantum chemical studies on corrosion inhibition for series of thio compounds on mild steel in hydrochloric acid

Quantum chemical calculations were performed on ten thio compounds using semi-empirical method PM3 within program package of Material Studio 5.5. The effect of molecular structure on the corrosion inhibition efficiency was investigated using the quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, (LUMO–HOMO) energy gap, dipole moment (λ) and fraction of electron transfer (ΔN) were calculated and discussed. A relationship between the corrosion inhibition efficiency and several quantum parameters was established with coefficient correlation (R²) of 0.8894.     

Corrosion inhibitors part V: QSAR of benzimidazole and 2-substituted derivatives as corrosion inhibitors by using the quantum chemical parameters

Quantum chemical SCF calculations of some parameters of benzimidazoles were correlated with their inhibition efficiency in case of steel in aqueous acidic medium. Geometric structures, total negative charge on the molecule (TNC), highest occupied molecular orbital (E_HOMO), lowest unoccupied molecular orbital (E_LUMO), dipole moment (μ) and linear solvation energy terms, molecular volume (Vi) and dipolar-polarization (π*) were correlated to corrosion inhibition efficiency. The correlation between quantum parameters obtained by AM1 calculation and experimental inhibition efficiency has been validated by single point calculations for the semi-empirical AM1 structure using B3LYP/6-31G* as a higher level of theory. Equations were proposed using linear regression analysis to calculate corrosion inhibition efficiency. It was established that the increase of the orbital energies E_HOMO favors the inhibition efficiency toward steel corrosion. The proposed linear equations were applied to predict the corrosion inhibition efficiency of some related structures in order to select molecules of possible activity from a library compounds.     

Corrosion inhibitors : Part II: Quantum chemical studies on the corrosion inhibitions of steel in acidic medium by some triazole, oxadiazole and thiadiazole derivatives

The corrosion inhibition efficiencies of some triazole, oxadiazole and thiadiazole derivatives for steel in presence of acidic medium have been studied by using AM1, PM3, MINDO/3 and MNDO semi-empirical SCF molecular orbital methods. Geometric structures, total negative charge on the molecule (TNC), highest occupied molecular energy level (E_HOMO), lowest unoccupied molecular energy level (E_LUMO), core-core repulsion (CCR), dipole moment (μ) and linear solvation energy terms, molecular volume (V_i) and dipolar-polarization (π^*), were correlated to corrosion inhibition efficiency. Four equations were proposed to calculate corrosion inhibition efficiency. The agreement with the experimental data was found to be satisfactory; the standard deviations between the calculated and experimental results ranged between ±0.03 and ±4.18. The inhibition efficiency was closely related to orbital energies (E_HOMO and E_LUMO) and μ. The correlation between quantum parameters and experimental inhibition efficiency has been validated by single point calculations for the semi-empirical AM1 structures using B3LYP/6-31G^** as a higher level of theory. The proposed equations were applied to predict the corrosion inhibition efficiency of some related structures to select molecules of possible activity from a presumable library of compounds.     

基于小波神经网络预测多相动态管道腐蚀速率

利用小波神经网络模型预测多相动态环境下油气集输管道腐蚀速率。首先通过室内多相动态腐蚀实验,获得了不同工况条件下的挂片腐蚀速率,用于训练和检验小波神经网络预测模型,然后利用多因子方差分析研究了温度、压力、流率、硫化氢含量、二氧化碳含量、溶解氧含量、含水率、盐含量和pH对腐蚀速率的影响程度,实现了各因素的有效性筛选,最后在确定隐含层节点数基础上通过训练、测试建立起适宜的小波神经网络预测模型,并进一步验证了模型可靠性。结果表明：除了压力外,各因素对腐蚀速率均有十分显著的影响,属于有效输入信号。当隐含层节点数为17时,8-17-1型小波神经网络结构表现出良好的准确性和稳定性。利用Levenberg Marquardt优化算法对模型进行了反复训练,直至其均方根误差小于容许收敛误差限0.001,预测值与实际值近似呈线性关系,训练、测试阶段决定系数分别为0.9992、0.9967,相关性较高,模型预测值和验证值亦不存在显著差异。因此小波神经网络预测模型对多相动态环境下油气集输管道腐蚀速率具有良好的预测能力。     

BP神经网络在炼油污水回用于循环水系统中腐蚀率的预测

介绍了BP神经网络的构造及基本原理,阐述了利用MATLAB的GUI建立BP模型的方法和步骤,并将其应用于炼油污水回用于循环冷却水系统腐蚀率的预测,建立一个以电导率和p H为输入向量、腐蚀率为输出向量的BP神经网络预测模型。结果表明,采用GUI建立的三层结构的BP神经网络模型,对炼油污水循环冷却水系统的腐蚀率的预测具有较高的预测精度。说明人工神经网络在循环水腐蚀预测中的应用是可行的,具有一定的应用价值。     

Experimental and theoretical investigation of the adsorption behaviour of new triazole derivatives as inhibitors for mild steel corrosion in acid media

Three triazole derivatives (4-chloro-acetophenone-O-1′-(1′,3′,4′-triazolyl)-metheneoxime (CATM), 4-methoxyl-acetophenone-O-1′-(1′,3′,4′-triazolyl)-metheneoxime (MATM) and 4-fluoro-acetophenone-O-1′-(1′,3′,4′-triazolyl)-metheneoxime (FATM)) have been synthesized as new inhibitors for the corrosion of mild steel in acid media. The inhibition efficiencies of these inhibitors were evaluated by means of weight loss and electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and polarization curves. Then the surface morphology was studied by scanning electron microscopy (SEM). The adsorption of triazole derivatives is found to obey Langmuir adsorption isotherm, and the thermodynamic parameters were determined and discussed. The relationship between molecular structure of these compounds and their inhibition efficiency has been investigated by ab initio quantum chemical calculations. The electronic properties such as the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels, energy gap (LUMO-HOMO), dipole moment and molecular orbital densities were computed.     

咪唑啉缓蚀剂合成工艺优化及吸附性能

以油酸、二乙烯三胺为原料,氧化钙为脱水剂,氯化苄为季铵化试剂,经酰胺化-环化、季铵化合成了新型咪唑啉季铵盐缓蚀剂,并对其吸附过程进行了研究.响应面法优化了油酸与二乙烯三胺摩尔比、环化时间和环化温度等合成关键工艺条件,采用红外光谱和可见光吸收光谱法分析产品结构,以动电位扫描极化曲线法评价缓蚀效果.以0.05mol油酸为基准,氧化钙0.10mol,氯化苄0.06mol,季铵化时间2.5h,季铵化温度55℃条件下,优化结果为:n(油酸):n(二乙烯三胺)为1:1.18,环化温度162.8℃,环化时间5.55h;在50℃缓蚀剂浓度200mg/L、15%盐酸溶液中缓蚀率可达94%;该缓蚀剂的吸附行为符合Langmuir 吸附等温式,为自发放热过程,50℃下吸附平衡常数为1.0277′10⁵L/mol,吉布斯自由能为-41.75kJ/mol,吸附热能为-54.07kJ/mol,熵值为-38.11J/(K·mol),属于以化学吸附为主的过程.与同类合成工艺相比较,环化温度明显降低,产物具有优异的缓蚀性能.     

NEW ARYLAZODYES AS CORROSION INHIBITORS FOR MILD STEEL IN HCl SOLUTION

Five arylazocyanoacetamide derivatives were investigated as corrosion inhibitors of mild steel in 2 M HCl solution using weight loss and galvanostatic polarization techniques. The inhibiting properties were found to depend on the concentration, the temperature, and the molecular structure of the compounds. Enhancement in inhibition efficiency of these compounds was observed on addition of KSCN due to synergism. The inhibitive action may be attributed to adsorption of inhibitor molecules on the active sites of the metal surface following the Frumkin adsorption isotherm. Thermodynamic parameters for the corrosion of mild steel in the presence and absence of the arylazocyanoacetamide derivatives have been calculated. Polarization curves indicate that these compounds act as mixed-type inhibitors. The correlation between inhibition efficiency and quantum chemical parameters has been investigated by PM3 quantum chemical calculation.