目的 提高硫脲咪唑啉类缓蚀剂在CO2/H2S共存体系中的缓蚀效果，并揭示缓蚀机理。方法 利用丙炔醇对硫脲基咪唑啉(TAI)进行改性得到双炔丙基甲氧基硫脲基咪唑啉(DPFTAI)，通过动态失重试验、极化曲线测试、交流阻抗测试分析其腐蚀性能。采用Material Studio 7.0软件模拟计算其分子轨道能量、Fukui指数、表面相互作用力和吸附状态、缓蚀剂分子与侵蚀性离子间的相互作用情况等，验证DPFTAI的缓蚀效果。结果 在不含H2S的条件下，TAI和DPFTAI的缓蚀效率均高于93%，当含有2000 mg/L H2S后，DPFTAI的缓蚀效率仍高达91.96%，且比TAI高出18.22%。模拟计算表明，DPFTAI有3个吸附中心，分别为其咪唑啉环上的2个N原子和DPFTAI分子侧链上的S原子，其与铁表面的相互作用能为29.66 kcal/mol，而TAI只有一个吸附中心，为其分子上的S原子，其与铁表面的相互作用能为22.46 kcal/mol;DPFTAI周围的HS^–浓度明显大于TAI周围的HS^–浓度。上述结果说明在CO2/H2S腐蚀体系中，DPFTAI在钢材表面的吸附效果明显优于TAI，因此缓蚀效果更好。结论 通过丙炔醇对TAI进行改性后，缓蚀剂DPFTAI抗CO2/H2S的腐蚀性能明显提高。吸附能力的提升是DPFTAI腐蚀抑制性能提高的主要原因。

Imidazoline thiourea oleate (TAI) is a very good corrosion inhibitor for carbon steel in CO2 corrosion environment, however its corrosion inhibition performance in CO2/H2S co-existence system is poor. In order to improve the corrosion inhibition effect for X65 steel in CO2/H2S corrosion environment, Propargyl alcohol is used to modify TAI to obtain a new corrosion inhibitor-dipropargyl methoxy thioureido-imidazoline (DPFTAI). In this article, the inhibition effect and mechanism of TAI and DPFTAI is studied by dynamic weight loss corrosion experiment and electrochemical tests, and the results shown the inhibition efficiency of DPFTAI is significantly improved. Material Studio 7.0 software is employed to calculate the molecular orbital energies of TAI and DPFTAI, adsorption energy of inhibitor, Fukui index, surface interaction force and adsorption state, the interaction between corrosion inhibitor molecules and corrosive ions, etc. The experiment results show that the inhibition efficiency of TAI and DPFTAI are both higher than 93% in the absence of H2S. When the H2S content is 2000 mg/L, the inhibition efficiency of DPFTAI is still as high as 91.96%, which is 18% higher than that of TAI. DPFTAI has three adsorption centers, namely two N atoms on the imidazoline ring and S atoms on the side chain of the molecule. The interaction energy between DPFTAI and iron surface is 29.66 kcal/mol. While TAI has only one adsorption center, which is S atom on the molecule, and its interaction energy with iron surface is 22.46 kcal/mol. The HS– concentration around CO2/H2S environment with DPFTAI inhibitor is significantly higher than that of TAI inhibitor, which further proves that DPFTAI has dramatically better adsorption effect and corrosion inhibition effect on carbon steel than TAI in CO2/H2S corrosion system.