月桂基咪唑啉硫酸酯盐对A3钢的缓蚀性能研究

Study on Corrosion Inhibition of A3 Steel by A Lauryl Imidazoline Sulfuric Ester

摘要:

以月桂酸和羟乙基乙二胺为原料，氨基磺酸为季铵化试剂，进行了季铵化反应，合成了咪唑啉缓蚀剂1-羟乙基-2-月桂基-咪唑啉硫酸酯盐（LIMS），并通过失重、极化曲线、交流阻抗和扫描电镜，研究了其在质量分数为10%的盐酸溶液中对A3钢的缓蚀性能及其表面的吸附行为。结果表明:该咪唑啉缓蚀剂在质量浓度为0.80g/L时，缓蚀效率为93.1%；添加缓蚀剂后，阳极/阴极反应作用系数fa和fc均<1，而且两者数值相近，说明可以同时抑制阴极和阳极反应过程，是一种混合型缓蚀剂；该缓蚀剂分子与金属表面的吸附符合Langmuir吸附等温式，能自发吸附于金属表面，以化学吸附为主；同样条件下，自制缓蚀剂LIMS缓蚀率为90.6%，优于市售缓蚀剂乌洛托品（78.5%）、苯并三氮唑（82.9%）、PS-1（84.2%）、IS2129（87.3%）。

Abstract:

An imidazoline corrosion inhibitor, 1-hydroxyethyl-2-lauryl imidazoline sulfuric ester (LIMS) was synthesized by quaternary ammonium reaction with lauric acid and N-hydroxyethyl-ethylenediamine as raw materials and amino sulfonic acid as the quaternarization reagent. Its corrosion inhibition performance and adsorption behavior to A3 steel in 10% hydrochloric acid solution were investigated by means of weight loss, polarization curve, electrochemical impedance spectroscopy (EIS) and environmental scanning electron microscope (ESEM). The results revealed that corrosion inhibition efficiency of up to 93.1% when LIMS at the mass concentration of 0.80g/L. After adding the corrosion inhibitor, anode/ cathode action coefficient fa and fc were lower than 1, both values were similar, LIMS could inhibit cathode and anode reaction simultaneously, was a mixed type inhibitor. The research also indicated that the adsorption of the inhibitor on A3 steel was in agreement with Langmuir adsorption isotherm and the inhibitor molecule was adsorbed into A3 steel surface spontaneously. In addition, chemisorption was the predominant mode of adsorption. The inhibition efficiency of LIMS was up to 90.6%, superior to that of urotropine（78.5%）, benzotrizaole（82.9%）, PS-1（84.2%）and IS2129（87.3%）under the same condition．