HCl介质中EDBDP对Q235钢的缓蚀性能研究

采用失重法和电化学法研究了O,O′-(苯甲基)二硫代磷酸-N,N-二乙铵(EDBDP)在HCl介质中对Q235钢的缓蚀性能,两种方法共同验证了EDBDP是一种优良的缓蚀剂。失重法研究表明:25±1℃时,在5%HCl溶液中,当EDBDP浓度为120 mg/L时,缓蚀率高达99.07%;电化学研究结果表明:EDBDP受HCl浓度、温度和待测时间的影响较小,属于混合型缓蚀剂。吸附拟合表明:EDBDP在Q235钢表面的吸附符合Langmuir吸附等温式,属于几何覆盖效应下的单分子层物理吸附。     

壳聚糖与CTAB复合缓蚀剂对Q235钢的缓蚀性能研究

采用失重法、交流阻抗法和极化曲线法研究了盐酸介质中壳聚糖及其与十六烷基三甲基溴化铵(CTAB)复合缓蚀剂对Q235钢的缓蚀性能。测试结果表明,单独使用壳聚糖作为缓蚀剂,对Q235钢表面有较强的缓蚀性能。当壳聚糖的质量浓度为0.1 g/L时,在1.0 mol/L的盐酸介质中30℃腐蚀24 h,3种方法测得的缓蚀效率均达到85%以上;加入CTAB后,缓蚀性能明显增强,CTAB的质量分数为10%时,缓蚀效率达到了92%以上。2种缓蚀剂在Q235钢表面吸附机理不同且吸附过程相互补充,因此二者复配后缓蚀性能加强。     

3-丁基5，5-二甲基海因咪唑季铵盐的 合成及缓蚀性能

以5,5-二甲基海因、1,4-二溴丁烷和咪唑为原料,经季铵化反应合成了一种化合物3-丁基-5,5-二甲基海因咪唑季铵盐(BDMHI),产率为62.9%,通过FTIR、~1HNMR、~(13)CNMR对产物结构进行了表征;采用失重法、极化曲线法、交流阻抗法、原子力显微镜研究了BDMHI在质量分数为6%的盐酸腐蚀介质中对Q235钢的缓蚀性能,并探讨了其在Q235碳钢表面的吸附行为。结果显示,在ρ(BDMHI)=1.0 g/L时,缓蚀效率可达91.25%;添加ρ(BDMHI)=0.05~0.8 g/L的缓蚀剂后,阴、阳极反应作用系数fc、fa均小于1且数值相近,表明能同时抑制Q235钢腐蚀的阴、阳极反应过程;缓蚀剂在Q235钢金属表面的吸附符合Langmuir吸附等温式,属于以化学吸附为主的混合吸附。     

1-(β-羟乙基)-2-混合脂肪基咪唑啉的制备及缓蚀性能

以地沟油水解产物混合脂肪酸和β-羟乙基乙二胺为原料,通过酰胺化-环化脱水缩合反应,合成了1-(β-羟乙基)-2-混合脂肪基咪唑啉,通过正交实验优化合成条件。结果表明,最佳合成条件为:混合脂肪酸和β-羟乙基乙二胺的质量比10∶4.6,酰化时间5 h,环化温度250℃,环化时间6 h。采用静态失重法、电化学极化曲线法考察了该化合物在5%HCl中对Q235钢的缓蚀性能。结果表明,在投药量100 mg/L、腐蚀时间6 h、温度60℃的实验条件下,碳钢的缓蚀率为95.43%,该缓蚀剂是一种混合型缓蚀剂。吸附热力学研究表明,缓蚀剂与金属表面的吸附符合Langmuir吸附等温式。     

1-(β-羟乙基)-2-混合脂肪基咪唑啉的制备及缓蚀性能

以地沟油水解产物混合脂肪酸和β-羟乙基乙二胺为原料,通过酰胺化-环化脱水缩合反应,合成了1-(β-羟乙基)-2-混合脂肪基咪唑啉,通过正交实验优化合成条件。结果表明,最佳合成条件为:混合脂肪酸和β-羟乙基乙二胺的质量比10∶4.6,酰化时间5 h,环化温度250℃,环化时间6 h。采用静态失重法、电化学极化曲线法考察了该化合物在5%HCl中对Q235钢的缓蚀性能。结果表明,在投药量100 mg/L、腐蚀时间6 h、温度60℃的实验条件下,碳钢的缓蚀率为95.43%,该缓蚀剂是一种混合型缓蚀剂。吸附热力学研究表明,缓蚀剂与金属表面的吸附符合Langmuir吸附等温式。     

植物提取物自组装膜在盐酸中对Q235钢的缓蚀作用

以铁线蕨植物提取物(ACE)为成膜物质,在Q235钢表面自组装得到缓蚀膜。通过极化曲线和电化学阻抗谱测试研究了该自组装膜对Q235钢在1 mol/L HCl溶液中的缓蚀性能。结果表明,该自组装膜对Q235钢的阴、阳极腐蚀反应均有抑制作用,可明显减缓Q235钢在盐酸溶液中的腐蚀,且缓蚀作用随ACE质量浓度的增大而增强。ACE分子在Q235钢表面的吸附遵从Langmuir和Frumkin吸附模型,为单分子层吸附,吸附分子之间存在横向吸引力。     

三嗪基聚醚双子咪唑啉缓蚀剂的合成及实验分析

以三聚氯氰为母体，分别引入一个长的聚醚链和两个油酸咪唑啉结构，既保证了良好的缓蚀性能，又增加了水溶性，设计合成了一种将多类有效缓蚀基团汇聚于一个结构中的新型缓蚀剂2,4-二油酸基咪唑啉-6-甲氧基聚乙二醇-1,3,5-三嗪(IPT)。通过失重、电化学技术、接触角、原子力显微镜（AFM）等手段测试了对Q235钢在1mol/L盐酸中的缓蚀性能，并分析了其作为缓蚀剂的缓蚀机理。所有结果均表明，IPT在1mol/L HCl中对Q235钢表现出优异的缓蚀效果，即使在70℃时，仍能保证在Q235钢表面稳定的吸附。除此之外，该缓蚀剂优化了传统咪唑啉类缓蚀剂的溶解度问题，缓蚀效果显著，具备良好的应用前景。     

两种甲基丙烯酸二甲氨乙酯基季铵盐的合成及缓蚀性能

以甲基丙烯酸二甲氨乙酯为母体,分别以氯丙烯和氯化苄为桥连基设计合成了两种季铵盐（DMA-1和DMA-2）。利用红外光谱、核磁共振氢谱证实了所得产物与设计相一致。再依次通过失重实验、电化学实验、AFM、接触角等手段测试了Q235钢在含有DMA-1 和DMA-2的1mol/L盐酸中的缓蚀性能,探讨了其在Q235钢表面的吸附和缓蚀机理。结果显示：在较高温度下,DMA-1和DMA-2仍能牢固吸附在Q235钢表面,当所加入缓蚀剂的浓度为100 mg/L 时,缓蚀率均可达92.7%以上,显示出良好的缓蚀性能,且 DMA-1比DMA-2具有更好的缓蚀效果。热力学计算结果表明DMA-1和DMA-2在Q235钢表面的吸附是化学吸附,过程自发、放热,且符合Langmuir等温吸附,属于良好的阳极型缓蚀剂。量子化学计算结果表明了DMA-1更容易提供或接受电子,进一步研究了DMA-1和DMA-2的分子结构与活性位点。     

二氧化氯缓蚀剂制备及性能研究

将多氨基磷酸盐、碳氢咪唑啉季铵盐、非离子表面活性剂、六亚甲基四铵和溶剂复配,制得二氧化氯缓蚀剂,采用静态失重法、电化学法评测缓蚀性能。研究了缓蚀剂对Q235、20#钢、304不锈钢、黄铜、铝试片在100,250,500,1 000 mg/L的二氧化氯溶液中的缓蚀情况。结果表明,在二氧化氯水溶液中加入ClO2缓蚀剂50～1 500 mg/L,可使标准试片Q235、20#钢、304不锈钢、黄铜、铝达到轻度腐蚀。     

一种新型联吡啶双子季铵盐的合成及缓蚀性能

以4,4'-联吡啶和氯化苄为原料,经季铵化反应制备了化合物1,1?-二苄基-4,4?-联吡啶双子季铵盐(PBA),产率为76.3%,通过FTIR、~1HNMR对产物结构进行了表征;利用失重法、电化学技术、AFM考察了PBA对1 mol/L盐酸溶液中Q235钢的缓蚀作用和其在Q235钢表面的吸附行为。结果表明,PBA是一种同时抑制阴、阳极的混合型缓蚀剂,缓蚀率随PBA浓度的增加而增加,随温度的升高而略有降低。当PBA质量浓度为80 mg/L时,缓蚀率可达96.53%。PBA在Q235钢表面的吸附为放热反应,遵循Langmuir等温式,是以化学吸附为主的混合型吸附。PBA在钢表面形成了一层致密的保护膜,大大阻碍了钢腐蚀。使用量子化学法研究了PBA的缓蚀机理,结果表明,PBA的活性区域集中于苯环和杂环上,且PBA分子接受电子的能力大于提供电子的能力。     

烯丙基硫脲对金属材料在盐酸中的缓蚀性能研究

文章通过静态失重法和电化学法对缓蚀剂烯丙基硫脲在盐酸体系中对金属材料的缓蚀性能进行了研究。分别考察了不同缓蚀剂浓度、挂片温度及不同金属材料等情况下烯丙基硫脲的缓蚀性能。结果表明,烯丙基硫脲对Q235碳钢的缓蚀性能较好,失重法实验结果表明,在20℃下,0.5 mol/L盐酸溶液中加入100 ppm烯丙基硫脲对不锈钢的缓蚀率可达93%;0.5 mol/L盐酸溶液中加入50 ppm烯丙基硫脲对Q235碳钢的缓蚀率可达94%。电化学法实验结果则表明,当烯丙基硫脲浓度达到1000 ppm时,对不锈钢的缓蚀率达到97%,对Q235碳钢的缓蚀率可达98%。     

A dissymmetric bis-quaternary ammonium salt gemini surfactant as effective inhibitor for Q235 steel in hydrochloric acid

The inhibition effect and adsorption behavior of a novel dissymmetric bisquaternary ammonium salt (DBAL) for Q235 steel in 1 M hydrochloric acid medium were investigated using weight loss method, polarization and electrochemical impedance spectroscopy (EIS). The result of weight loss method indicates that the inhibition efficiency increased with DBAL concentration and temperature in the studied range. The inhibition efficiency is above 90% at a concentration of 3.28 × 10⁻⁴ M in the temperature range of 298–328 K. The polarization measurements reveal that DBAL is a mix-type inhibitor which mainly inhibits cathodic process. EIS results show that changes in the impedance parameters (R_ct and C_d) were due to the formation of a protective layer on the Q235 steel surface by the adsorption of inhibitor molecules. Adsorption follows the Langmuir isotherm via chemical adsorption on the Q235 steel surface. Thermodynamic and kinetic parameters were evaluated from the effect of temperature on corrosion and inhibition processes to discuss the adsorption mechanism.     

Starch-AA-CS三元共聚物对酸溶液中碳钢的缓蚀作用

以淀粉（Starch）、丙烯酸（AA）和壳聚糖（CS）为原料合成三元共聚物（SAAC）。利用红外光谱（FT-IR）和X射线衍射（XRD）进行结构表征,并通过电化学方法、失量法、扫描电子显微镜（SEM）和能谱仪（EDS）研究SAAC在1 mol·L^-1 HCl环境下对Q235碳钢的缓蚀作用及机理。结果显示,SAAC是一种混合型缓蚀剂,30℃时,200 mg·L^-1的SAAC的缓蚀率可达90.1%。通过Gibbs自由能和Tafel曲线可知,SAAC在Q235碳钢表面的吸附符合Langmuir吸附等温式,同时存在物理吸附与化学吸附。SAAC合成原料经济、环保,合成条件温和,是一种具有广泛应用前景的绿色环保型缓蚀剂。     

离子液体在甲醇/硫酸介质中对Q235钢表面的缓蚀性能

探究硫酸存在时Q235钢在甲醇中的腐蚀行为,以及离子液体1-丁基-3-甲基咪唑氯盐([Bmim]Cl)对金属表面的缓蚀作用。通过静态失重法、电化学测试、扫描电子显微镜来测定[Bmim]Cl对Q235钢的缓蚀性能。并利用量子化学计算和分子动力学模拟分析[Bmim]Cl分子的缓蚀机理。在甲醇中随着硫酸含量的增加碳钢的腐蚀速率增加。含有59.51 ml 0.05 mol·L^-1H₂SO₄的甲醇溶液作为腐蚀介质时,随着[Bmim]Cl浓度升高,缓蚀效率逐渐增大,当浓度为0.6 mol·L^-1时,缓蚀效率达到最佳值,为90.63%,且[Bmim]Cl是主要控制阳极反应的混合抑制剂,SEM分析表明在含有缓蚀剂溶液中浸泡后的Q235钢表面相对于未加缓蚀剂更加平整。前线轨道分析和Fukui指数都表明,离子液体在碳钢表面的吸附位点分布在咪唑环上,与Fe发生化学吸附。分子动力学模拟结果表明缓蚀剂分子以阳离子[Bmim]⁺平行吸附于金属表面,阴离子Cl^-扩散在溶液中的方式达到缓...     

Synthesis,Characterization and Inhibition Performance of Vanillin‐Modified Chitosan Quaternary Ammonium Salts for Q235 Steel Corrosion in HCl Solution

In order to enhance the solubility of chitosan in water and its corrosion inhibition performance on Q235 steel in 1 M HCl solution, N‐vanillyl‐O‐2′‐hydroxypropyltrimethylammonium chloride chitosan (VHTC) was synthesized. The structure of VHTC was characterized by FT‐IR and ¹H‐NMR spectroscopy. The corrosion inhibition performance of VHTC on Q235 steel in 1 M HCl solution was studied by weight loss, polarization, electrochemical impedance spectroscopy (EIS) and stereo microscope analysis. Experimental results indicate that VHTC shows better inhibition efficiency compared to chitosan. When the concentration of VHTC increases to 200 mg L^?1, the inhibition efficiency reaches 90 %, which is almost equal to the conventional corrosion inhibitors (e.g., imidazoline). The polarization study demonstrates that VHTC is a mixed‐type inhibitor caused by a geometrical blanketing effect. The charge transfer resistance is proportional to the inhibitor concentration as revealed by the EIS results, indicating that the protective film on the Q235 steel surface is formed by adsorption of the inhibitor molecules. The inhibition efficiency of VHTC achieves the maximum value within 24 h when the concentration of VHTC is 200 mg L^?1. The morphology observation of the corroded steel surface indicates that the corrosion of Q235 steel in 1 M HCl solution is significantly inhibited after introducing VHTC into the acidic solution.     

THE EFFECT OF ENVIRONMENTALLY BENIGN FRUIT EXTRACT OF SHAHJAN (MORINGA OLEIFERA) ON THE CORROSION OF MILD STEEL IN HYDROCHLORIC ACID SOLUTION

The inhibition of the corrosion of mild steel in hydrochloric acid solution by the fruit extract of shahjan (Moringa oleifera) was studied using weight loss, electrochemical impedance spectroscopy (EIS), linear polarization, and potentiodynamic polarization techniques (Tafel). Inhibition was found to increase with increasing concentration of the extract. The effect of temperature, immersion time, and acid concentration on the corrosion behavior of mild steel in hydrochloric acid solutions with addition of extract was also studied. The inhibition occurred via adsorption of the inhibitor molecules on the mild steel surface obeying the Langmuir adsorption isotherm. Thermodynamic activation parameters such as activation energy, enthalpy (ΔH*), and entropy (ΔS*) of activation for corrosion process were calculated and discussed. The results obtained show that both chemical and physical adsorption of inhibitor molecules occur simultaneously and the fruit extract of shahjan (Moringa oleifera) could serve as an effective inhibitor of the corrosion of mild steel in hydrochloric acid media.     

Corrosion Inhibition of Mild Steel in Acidic Medium by Linseed Oil-Based Imidazoline

A new kind of corrosion inhibitor (LOBI) based on linseed oil has been synthesized. The molecular structure of LOBI was investigated using Fourier transform infrared spectroscopy and nuclear magnetic resonance spectrometer. Its inhibiting behavior on mild steel in 1.0 M HCl was studied by electrochemical potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. Results reveal that LOBI was a good mixed-type inhibitor. The adsorption of LOBI at 40 °C obeys the Langmuir adsorption isotherm. The N(1s) and S(2p) peaks of XPS measurement indicate that LOBI has been adsorbed onto a Q235 steel surface. The adsorption equilibrium constant, adsorption free energy and activation energy were also calculated, which indicated the adsorption of LOBI was chemisorption.