3-(吗啉基甲基)-苯并噻唑-2-硫酮的合成与缓蚀性能

Composition and Inhibition Performance of 3-(Morpholinomethyl)-Benzothiazole-2-Thione

目的研究3-(吗啉基甲基)-苯并噻唑-2-硫酮(MLMBT)的缓蚀性能。方法在微波辐照下用2-巯基苯并噻唑、甲醛和吗啡啉合成了MLMBT,采用失重法和动电位极化曲线测试了其缓蚀性能,利用分子动力学模拟方法探讨了其在Fe表面的吸附作用。结果该缓蚀剂能有效抑制N80钢CO2腐蚀,属于混合型缓蚀剂。在90℃和其加量为0.5 g/L时,能使腐蚀速率从0.3691 g/(m2·h)降低到0.1048 g/(m2·h)。其分子中最高占据轨道(HOMO)的电荷主要分布在分子中的N,S原子上,而其最低空轨道(LUMO)的电荷则主要分布在巯基苯并噻唑环上,当其在N80钢表面发生吸附时,分子中的巯基苯并噻唑环和吗啉基处于同一平面而同时平行吸附。结论分子动力学模拟结果从微观角度验证了MLMBT具有良好缓蚀性能,与失重法和电化学测试结果一致。

Objective To research corrosion performance of 3-（morpholinemethyl）-benzothiazole ketone-2-sulfur（MLMBT）. Methods TMLMBT was synthesized under micro-wave irradiation with 2-mercaptobenzothiazole, formalinand morpholine under microwave irradiation. The inhibition performance of the compound was measured based on weightloss and polarization curve methods. The adsorption behavior of the compound on Fe surface was analyzed through moleculardynamics simulation. Results The inhibitor could efficiently inhibit corrosion of N80 steel in simulated corrosivemedium of saturated C 02 environment. It belonged to the mixed type. When the dosage was 0.5 g/L and at 90 Xl, thecorrosion rate could be reduced from 0.3691 g/（m2-h） to 0.1048 g/（m2-h）. The electric charge of the highest occupied molecularorbit （HOMO） of the inhibitor molecules was mainly distributed on N and S atoms, and that of the lowest unoccu- pied molecular orbit （LUMO） was mainly distributed on the mercaptobenzothiazole ring. While the inhibitor moleculeswere adsorbed on the surface of Fe, the mercaptobenzothiazole ring and morpholine group of the molecules were arrangedin the same plane and adsorbed abreast to the Fe surface. Conclusion The results of molecular dynamics simulations verifythe good corrosion inhibition performance of MLMBT inhibitors from the microscopic point of view, which is consistentwith the results of weight loss and electrochemistry.