基于盐酸酸洗的含氮有机缓蚀剂制备、缓蚀性能及机理研究

发布时间：2018-03-24 22:31

本文选题：腐蚀　切入点：缓蚀剂　出处：《西南石油大学》2015年博士论文

【摘要】：金属的腐蚀遍及国民经济生产的各个部门及行业。腐蚀问题不仅耗费了宝贵的国家资源,造成巨大的经济损失,而且还使产品的质量下降,对环境造成恶劣影响,甚至造成重大安全事故,现已成为工业和科学技术发展的绊脚石。缓蚀剂在金属防护工程中占有重要的地位,能够有效阻止金属腐蚀,起到保护金属材料的作用。随着人们环境保护意识的增强和绿色化学概念的提出,低毒、高效、环境友好已成为未来缓蚀剂技术发展的新趋势。基于上述理念,针对盐酸酸洗过程中带来的金属腐蚀问题,本论文合成了五种酰腙化合物和四种芳醛缩胺类Schiff碱化合物,选取了一种双子表面活性剂,并通过失重实验,电化学实验,量子化学计算及扫描电镜分析等方法评价了上述化合物在1mol/L盐酸溶液中对碳钢的缓蚀性能,分析了它们对碳钢的缓蚀机理。本文的研究对于丰富合成型缓蚀剂的种类具有重要意义。本论文研究的主要成果如下：1、制备了五种酰腙化合物,并优化了其合成条件。实验结果表明,五种酰腙化合物均能较好的抑制碳钢在1 mol/L盐酸溶液中的腐蚀反应。随着酰腙化合物浓度不断增大,缓蚀效率逐渐升高；随着酸性介质温度升高,缓蚀效率呈减小趋势；随着浸泡时间的增长,缓蚀效率逐渐下降。五种酰腙化合物均为混合抑制型缓蚀剂。该类化合物分子在碳钢表面的吸附行为符合Langmuir吸附模型,能够在金属表面形成稳定的自组装膜,有效阻止了金属被酸液腐蚀,从而达到了保护金属材料的目的。该类缓蚀剂在金属表面的吸附是物理吸附和化学吸附共同作用的结果,其中以化学吸附为主。2、制备了四种芳醛缩胺类Schiff碱化合物。实验结果表明,四种芳醛缩胺类Schiff碱化合物均能抑制碳钢在1 mol/L盐酸溶液中的腐蚀反应。随着所选化合物浓度不断增大,缓蚀效率逐渐升高。四种芳醛缩胺类Schiff化合物均为混合抑制型缓蚀剂。研究发现这四种化合物在碳钢表面的吸附行为符合Langmuir吸附模型,为单分子层吸附,能够金属表面形成稳定规则的自组装膜,起到了保护金属的目的。由吉布斯自由能变判断该类缓蚀剂分子在碳钢表面的吸附是物理吸附和化学吸附共同作用的结果,其中以化学吸附为主。3、选取了双子表面活性剂DSH作为研究对象。由量子化学计算可知DSH是平行共面的反向结构。实验结果表明,DSH能较好的抑制碳钢在1 mol/L盐酸溶液中的腐蚀,随着DSH浓度不断增大,缓蚀率逐渐升高；随着酸性介质温度升高,缓蚀率减小。DSH为混合抑制型缓蚀剂,能同时抑制碳钢的阳极溶解和阴极析氢反应。该缓蚀剂分子在碳钢表面的吸附行为符合Langmuir吸附模型,在金属表面形成的吸附膜阻碍金属发生腐蚀,达到了保护金属的目的。DSH在碳钢表面的吸附是物理吸附和化学吸附共同作用的结果,从理论上分析物理吸附和化学吸附的作用程度相当,且是自发进行的。多种测试方法得到的缓蚀率结果具有较好的一致性。由失重实验数据,求得如吉布斯自由能变、熵变、焓变等相关的热力学参数,在分析这些参数的基础上,探讨了双子表面活性剂的缓蚀吸附作用机理。
[Abstract]:The metal corrosion and the various departments and sectors of the national economy production throughout. Corrosion problems not only consume valuable resources of the country, causing huge economic losses, but also make the quality of the products decreased, causing adverse effects on the environment, and even cause major accidents, has now become a stumbling block to the industry and the development of science and technology. The inhibitor occupies the important status in the metal protection project, can effectively prevent metal corrosion, play a role in the protection of metal materials. As proposed, the awareness of environmental protection and green chemistry concept of low toxicity, high efficiency, environmental friendly has become a new trend in the future development of corrosion inhibitor technology. Based on the above concept, aiming at the problem of metal corrosion causes hydrochloric acid pickling process, this paper synthesized five hydrazone compounds and four kinds of aromatic aldehyde amine Schiff base compounds selected a Gemini surfactant, and Through weight loss experiment, electrochemical experiment, quantum chemical calculations and scanning electron microscopy to evaluate the corrosion performance of the above compounds on carbon steel in 1mol/L hydrochloric acid solution, analyzes their influence on the corrosion inhibition mechanism. This research can enrich the synthetic inhibitor species has important significance. The main results of this paper are as follows: 1, five hydrazone compounds were prepared, and the optimal synthesis conditions. The experimental results show that five hydrazone compounds could inhibit the corrosion reaction of carbon steel in 1 mol/L HCl solution better in hydrazone compounds. With the concentration increasing, the inhibition efficiency increased gradually with the acidic medium; the temperature increased, the inhibition efficiency decreased; with the dipping time, the inhibition efficiency decreased gradually. Five hydrazone compounds were mixed type inhibitors. The compounds on the carbon steel surface The adsorption behavior of the Langmuir model of adsorption, can form SAMs on the metal surface, effectively preventing the metal by the acid corrosion, so as to achieve the purpose of protection of metal materials. The inhibitor is adsorbed on the metal surface is physical adsorption and chemical adsorption results, the chemical adsorption of.2. Four kinds of aromatic aldehyde amine Schiff base compounds were prepared. The experimental results show that the corrosion reaction of four kinds of aromatic aldehyde amine Schiff base compounds inhibited carbon steel in 1 mol/L HCl solution. With the selected compounds concentration increases, the inhibition efficiency increased gradually. Four kinds of aromatic aldehyde amine compounds were Schiff a mixed type inhibitor. The study found that the four kinds of compounds with Langmuir adsorption model on adsorption behavior of carbon steel surface, as the single molecular layer adsorption to SAMs formed stable rules of metal surface, To protect the metal. The Gibbs free energy of judgment of the inhibitor molecule is physical adsorption and chemical adsorption. Adsorption on the surface of carbon steel, in which the chemical adsorption of.3, selected the Gemini surfactant DSH as the research object. By quantum chemical calculation shows that DSH is a reverse parallel structure coplanar. Experimental results show that the DSH corrosion in 1 mol/L HCl solution in the inhibition of steel better, with DSH concentration increasing, the inhibition rate increased gradually; with the acidic medium temperature, the corrosion rate decreases with.DSH for suppression of mixed type inhibitor, can inhibit the anodic dissolution and cathodic carbon steel hydrogen reaction. The inhibitor molecules adsorption on surface of carbon steel with Langmuir adsorption model. The adsorption film formed on the metal surface barrier metal corrosion, to protect the metal to.DSH in carbon steel sheet The adsorption is physical adsorption and chemical adsorption. Rather, the extent of physical adsorption and chemical adsorption in theory, and is spontaneous. Get a variety of testing methods of corrosion inhibition rate consistent with the results. The experimental data obtained by weight loss, such as the Gibbs free energy, entropy, thermodynamics the enthalpy change of related parameters, based on the analysis of these parameters, discusses the corrosion inhibition and adsorption mechanism of Gemini surfactants.

【学位授予单位】：西南石油大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG174.42

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