天然棕榈酸改性缓蚀剂的制备及其抗CO₂腐蚀的性能研究

【作者】 刘鹤鸣；

【导师】 杜海燕；

【作者基本信息】 江西理工大学 ， 应用化学， 2008， 硕士

【摘要】 本课题以天然乌桕脂中提取出来的重要化工原料棕榈酸为主要原料,通过酰氯化法、酰胺化法两步合成法对其进行改性制备了两种环境友好的缓蚀剂,即棕榈双酰胺和棕榈酰基硫脲。通过单因素实验和正交试验法确定了合成目标产物的最佳工艺条件,并通过红外光谱（IR）测试,熔点测试以及热重/差热（TG/DTA）分析对目标产物进行了表征。实验结果表明:合成反应中间体棕榈酰氯的最优化实验条件:原料棕榈酸与二氯亚砜的投料摩尔比为1∶1.5,反应温度为70℃,反应时间为4 h,在该条件下中间体棕榈酰氯的产率为96.8%;合成目标产物棕榈双酰胺的最优化实验条件:投料摩尔比（棕榈酰氯/无水乙二胺）为3.5∶1.0,反应温度为90℃,反应时间为1 h,该条件下棕榈双酰胺的产率达97.6%,该产品熔点为140℃～144℃,在160℃前表现出良好的热稳定性;合成目标产物棕榈酰基硫脲的最优化实验条件:投料摩尔比（棕榈酰氯/硫脲）为3.0∶1.0,反应温度为80℃,反应时间为1 h,该条件下棕榈酰基硫脲的产率达94.2%,该产品熔点为182℃～186℃,在148℃前表现出良好的热稳定性。利用传统的高温高压静态腐蚀失重法,再结合现代的电化学方法（开路电位、线性极化电阻、Tafel极化曲线、交流阻抗谱）和电镜扫描等方法对两种目标产物在含饱和CO₂模拟油田采出液中对油气田管线钢X65碳钢的缓蚀性能及缓蚀机理进行了研究和探讨,实验结果表明:棕榈双酰胺和棕榈酰基硫脲在含饱和CO₂模拟油田采出液中对油气田管线钢X65碳钢均具有良好的缓蚀效果,在棕榈双酰胺添加浓度为0.20 g·L^-1时,缓蚀效率达82%以上;棕榈酰基硫脲添加浓度为0.25 g·L^-1时,缓蚀效率达84%以上;并且两种缓蚀剂同属于以阳极抑制型为主的阳极型缓蚀剂,通过覆盖效应产生缓蚀作用;两种缓蚀剂经复配后,缓蚀效率比使用单一缓蚀剂时要低,说明两种缓蚀剂具有拮抗（负协同）效应。更多还原

【Abstract】 Two environmental-friendly corrosion inhibitors were synthesized through acyl-chloridation and acyl-amidation by modifying crude palmitic acid which as mostly raw material. The two corrosion inhibitors are palmityl amide and palmityl acylthiourea. The optimum condition of synthesizing aim products were decided by orthogonal experiments. The basic characters of aim products were affirmed by testing IR spectra, melting point and TG/DTA, and the superficial performance of its such as emulsion capability, dispersion capability etal were also tested. The results showed that the optimum condition of synthesizing middle product was: molar ratio of materials （crude palmitic acid/sulfurous oxychloride） is 1.0:1.5, reaction temperature is 70℃, reaction time is 4 h, the yield of palmityl chloride in this reaction condition is 96.8%; the optimum condition of synthesizing aim product palmityl amide was: molar ratio of materials （palmityl chloride/ethylenediamine） is 3.5:1.0, reaction temperature is 90℃, reaction time is 1 h, the yield of palmityl amide in the reaction condition is 97.6%; the optimum condition of synthesizing the other aim product palmityl acylthiourea was: molar ratio of materials （palmityl chloride/ thiocarbamide） is 3.0:1.0, reaction temperature is 80℃, reaction time is 1 h, the yield of palmityl acylthiourea in this reaction condition is 94.2%.The inhibiting action of the two aim products as corrosion inhibitor on the carbon dioxide corrosion of X65 mild steel in simulated oil field produced water with saturated CO₂ was studied by using static weight-loss experiment, electrochemical techniques containing Tafel polarization curve measurement, polarization resistance measurement and electrochemical impedance spectroscopy（EIS） measurement, and scanning electron microscopy measurement. The experimental results revealed that the two aim products-palmityl amide and palmityl acylthiourea act as good inhibitor of X65 mild steel in simulated oil field produced water with saturated CO2. The inhibition efficiency of palmityl amide attain up to 82% when its concentration is 0.20 g·L^-1, and the inhibition efficiency of palmityl acylthiourea attain up to 84% when its concentration is 0.25 g·L^-1. Tafel polarization curves reveal that the two aim products are belonged to anodic type inhibitor. EIS show that the corrosion protection can be explained by the chemical adsorption, and the inhibition was due to the blocking effect. Polarization curve measurement and EIS measurement show that the two aim product has no synergistic inhibition effect after they are complexed.更多还原