桐油水解制备咪唑啉缓蚀剂及其量子化学研究

目的 开发原料价廉易得、能实际应用的缓蚀剂。方法 以桐油为原料，水解后得到桐油酸，然后与二乙烯三胺经过酰胺化和环化反应，生成桐油咪唑啉缓蚀剂。在模拟现场环境的条件下对所合成的桐油咪唑啉缓蚀剂进行电化学测试和高温高压性能评价。利用量子化学计算对桐油咪唑啉缓蚀剂的分子动力学进行模拟，探讨其在Fe表面的吸附作用。结果 红外光谱显示，桐油水解后可生成桐油酸，最终合成物为桐油咪唑啉。电化学测试表明，随着桐油咪唑啉缓蚀剂添加量的增大，20#测试钢片的自腐蚀电位逐渐提高，腐蚀电流降低。高温高压模拟实验显示，加入油酸咪唑啉后，腐蚀速率明显降低，由0.3181 mm/a降到了0.0392 mm/a。量子化学计算表明，桐油咪唑啉分子中的咪唑啉环会平行吸附于铁表面，形成一层缓蚀剂膜。结论 价廉易得的桐油经水解后可得桐油酸，再与二乙烯三胺经过酰胺化和环化反应最终合成了桐油咪唑啉缓蚀剂。该缓蚀剂添加量越大，对20#钢片的缓蚀效果越好，呈现出了较好的缓蚀效果，其分子结构中的咪唑环能平行吸附于铁表面，属于抑制阳极型缓蚀剂。

Preparation of Imidazoline and Its Quantum Chemistry by Hydrolysis of Tung Oil

The work aims to develop corrosion inhibitors that can be made of cheap and available raw materials and applied in practice. Tung oil was hydrolyzed to obtain tung oleic acid, and then aminated and cyclized with diethylenetriamine to form tung oil imidazolin corrosion inhibitor. The electrochemical test and high temperature and high pressure performance evaluation were carried out to the synthesized tung oil imidazolin corrosion inhibitor under the simulated field environment. The molecular dynamics of tung oil imidazolin corrosion inhibitor was simulated by quantum chemical calculation, and its adsorption on Fe surface was discussed. Infrared spectra showed that tung oil could form tung oleic acid after hydrolysis, and the final compound was tung oil imidazolin. The electrochemical test showed that with the increase of the amount of tung oil imidazolin corrosion inhibitor, the self-corrosion potential of the 20# steel sheet increased gradually and the corrosion current decreased. The simulation results of high temperature and high pressure test showed that the corrosion rate decreased obviously after the addition of imidazolin oleate, from 0.3181 mm/a to 0.0392 mm/a. Quantum chemical calculation showed that the imidazolin ring in tung oil imidazolin molecule was adsorbed on the iron surface in parallel, forming a layer of corrosion inhibitor film. Tung oil acid can be obtained by hydrolysis of cheap and available tung oil, and then synthesized with diethylenetriamine by amidation and cyclization to form tung oil imidazolin corrosion inhibitor. The increase of the amount of the inhibitor improves the resistance of corrosion medium transfer and slows down the corrosion of 20# steel sheet, showing a good corrosion inhibition effect. The imidazole ring in the molecular structure can be adsorbed on the iron surface in parallel, so the inhibitor is anode-inhibiting corrosion inhibitor.