新型有机衍生物缓蚀剂的制备与性能

发布时间：2018-08-22 09:22

【摘要】：缓蚀剂是一种以适当的浓度和形式存在于环境(介质)中时,可以防止或减缓材料腐蚀的化学物质或几种化学物质的混合物,在众多腐蚀控制方法中,添加缓蚀剂成为了一种简单,有效,适用性强的重要的防腐蚀手段,特别是在酸性腐蚀介质中添加有机缓蚀剂已广泛应用于石油化工和锅炉酸洗等行业。有机缓蚀剂分子结构中常含有氮、氧、硫、不饱和键或芳香环的极性基团,它们可以通过静电相互作用或通过配位共价键吸附在金属表面,并形成一层保护膜。本论文主要合成了两种有机小分子:三苯胺二醛(TD)和胞嘧啶-L-丙氨酸(CLAD),选用生物大分子脱氧核糖核苷酸(DNA)作为缓蚀剂,研究了三种有机分子作为碳钢在强酸介质中的缓蚀性能和机理,主要内容如下:(1)本文将三苯胺进行氧化反应得到三苯胺二醛,并研究其与精氨酸,碘化钾(KI)形成的复合物对碳钢在1 MHC1溶液中的缓蚀性能。失重法发现当配方为:50 mg·L-1三苯胺二醛+50 mg·L-1精氨酸+100 mg·L-1碘化钾时,其缓蚀效率高达92%;该复合缓蚀剂作为混合型缓蚀剂在金属表面吸附符合等温吸附理论,EDS分析结果验证复合缓蚀剂吸附在金属表面,形成一层良好的保护膜,同时对碘化钾的协同作用机理也展开探讨;量子化学计算结果表明,三苯胺二醛与精氨酸含有的极性基团能够起到稳定地吸附作用,并通过建立简易的吸附模型进行解释。(2)利用分子设计手段,将L-丙氨酸和胞嘧啶生物小分子通过脱水缩合反应合成有机化合物胞嘧啶-L-丙氨酸,作为一种环境友好型缓蚀剂,用于X80钢在0.5 M HC1溶液中。利用失重法、极化曲线法、电化学阻抗谱(EIS)和SEM法系统地研究胞嘧啶-L-丙氨酸的缓蚀性能。结果表明胞嘧啶-L-丙氨酸的最高缓蚀效率达到91%,远高于单独使用丙氨酸的78%;形成的致密保护膜有效地阻碍电子的转移,降低金属溶解和腐蚀进程;该有机缓蚀剂的吸附过程遵循等温吸附理论,且吸附类型包含物理吸附和化学吸附;量子化学计算参数表明高缓蚀率主要源于胞嘧啶-L-丙氨酸较强的吸附能力。此外,当胞嘧啶-L-丙氨酸与碘化钾复合后,在进一步提高缓蚀效率的同时还降低成本。(3)采用生物大分子DNA作为碳钢在1 M HC1溶液中的缓蚀剂,并利用失重法和电化学方法研究其缓蚀效果,以吸附理论,红外光谱,XPS和量子化计算探索其缓蚀机理。研究发现,DNA缓蚀剂在浓度为20 mg·1-1时,缓蚀效率达到92%;同时DNA分子的吸附遵循朗格谬等温吸附理论,红外光谱结果表明DNA分子在成膜前后结构发生了变化,原因是与金属表面发生相互作用;XPS表征进一步表明金属表面含有DNA的元素,并与之形成Fe-N键和Fe-O键,量子化学计算结果进一步表明DNA缓蚀剂分子向铁原子d轨道提供孤对电子,形成稳固的配位化学键。该研究证明了低用量DNA优异的缓蚀性能和阐明了对应缓蚀机理。
[Abstract]:An inhibitor is a chemical substance or a mixture of several chemicals that can prevent or slow down the corrosion of a material when it is present in the environment (medium) at an appropriate concentration and form, among many corrosion control methods, The addition of corrosion inhibitor has become a simple, effective and suitable way to prevent corrosion. Especially, the addition of organic corrosion inhibitor in acid corrosion medium has been widely used in petrochemical industry and boiler pickling industry. The molecular structures of organic corrosion inhibitors often contain polar groups of nitrogen, oxygen, sulfur, unsaturated bonds or aromatic rings, which can be adsorbed on the metal surface by electrostatic interaction or by coordination covalent bonds, and form a protective film. In this paper, two kinds of organic small molecules, trianiline dialdehyde (TD) and cytosine L-alanine (CLAD), were synthesized. The biomacromolecular deoxyribose nucleotides (DNA) were used as corrosion inhibitors. The corrosion inhibition properties and mechanism of three organic molecules used as carbon steel in strong acid medium were studied. The main contents are as follows: (1) Trianiline dialdehydes were prepared by oxidation of trianiline and arginine. Inhibition of corrosion of carbon steel by potassium iodide (KI) complex in 1 MHC1 solution. It was found by weightlessness that when the formula was 1: 50 mg L-1 trianiline dialdehyde 50 mg L-1 arginine 100 mg L-1 potassium iodide, The corrosion inhibition efficiency is as high as 92.The composite inhibitor acts as a mixed inhibitor to adsorb on the metal surface in accordance with the isothermal adsorption theory and EDS analysis results show that the composite inhibitor adsorbs on the metal surface and forms a good protective film. At the same time, the synergistic mechanism of potassium iodide was also discussed. The results of quantum chemical calculation showed that the polar groups contained in trianiline dialdehydes and arginine could be adsorbed stably. A simple adsorption model was established. (2) the organic compound cytosine L-alanine was synthesized by dehydration and condensation reaction of L-alanine and cytosine biological small molecules by molecular design as an environment-friendly corrosion inhibitor. It is used in X80 steel in 0.5m HC1 solution. The corrosion inhibition of cytosine L-alanine was systematically studied by weightlessness method, polarization curve method, electrochemical impedance spectroscopy (EIS) and SEM method. The results show that the highest corrosion inhibition efficiency of cytosine L-alanine is 91%, which is much higher than that of 78% alanine alone, and the dense protective film can effectively block the electron transfer and reduce the process of metal dissolution and corrosion. The adsorption process of the organic corrosion inhibitor follows the isothermal adsorption theory, and the adsorption types include physical adsorption and chemical adsorption, and the quantum chemical calculation parameters show that the high corrosion inhibition rate is mainly due to the strong adsorption capacity of cytosine-L-alanine. In addition, when cytosine -L-alanine was combined with potassium iodide, the corrosion inhibition efficiency was further improved and the cost was also reduced. (3) Biomacromolecule DNA was used as corrosion inhibitor for carbon steel in 1m HC1 solution. The inhibition effect was studied by weightlessness method and electrochemical method. The corrosion inhibition mechanism was explored by adsorption theory, IR XPS and quantization calculation. It was found that the inhibition efficiency reached 92when the concentration of DNA inhibitor was 20mg 1-1. Meanwhile, the adsorption of DNA molecules followed Langermal isotherm adsorption theory, and the IR spectra showed that the structure of DNA molecules changed before and after the film formation. The reason is that the interaction between DNA and metal surface further indicates that the metal surface contains the elements of DNA and forms Fe-N bond and Fe-O bond. The quantum chemical calculation further indicates that the DNA inhibitor molecule provides lone pair electrons to the d orbital of iron atom. Form a solid coordination chemical bond. This study proved the excellent corrosion inhibition performance of low dosage DNA and explained the corresponding corrosion inhibition mechanism.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.42

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