一种基于膦甲基化曼尼希碱缓蚀剂的合成与性能评价

二氧化碳驱油引起的腐蚀是石油工业中一种比较常见的腐蚀类型，缓蚀剂的研发与应用可以有效抑制金属设备的腐蚀。本文以N-乙烯叱咯烷酮、苯胺、甲醛为原料制备了曼尼希碱中间体，最后采用甲醛、亚磷酸对中间体改性得到一种甲基化结构的曼尼希碱。并通过红外光谱、核磁共振氢谱对膦甲基化曼尼希碱进行了结构表征，通过静态失重试验、电化学方法和扫描电镜分析了膦甲基化曼尼希碱的缓蚀性能及机理。实验结果表明：静态失重试验中，当膦甲基化曼尼希碱加量为600mg/L时，腐蚀速率为0.062 mm/a，低于石油与天然气行业标准0.076mm/a；在动电位极化曲线中发现，随着膦甲基化曼尼希碱加量的增加，极化曲线呈现向阴极偏移的趋势，且总体偏移趋势小于85mV，表明膦甲基化曼尼希碱主要是通过抑制阴极反应为主的混合型缓蚀剂；从能谱测试结果中可以看出，添加膦甲基化曼尼希碱缓蚀剂的钢片相比于空白钢片表面则新出现氮、硫、磷元素，印证了杂原子中的孤电子在金属表面的吸附理论，可以起到抑制或减缓腐蚀的作用。

Synthesis and Perfrmance Evaluation of a Phosphine Methylated Mannich Base Corrosion Inhibitor

Corrosion caused by CO₂flooding is a relatively common type of corrosion in the petroleum industry. The development and application of corrosion inhibitors can effectively inhibit the corrosion of metal equipment. In this paper，theMannich base intermediate MPV was prepared withn-vinylchirolidone,aniline and formaldehyde as raw materials. Finally,the intermediate MPV was modified with formaldehyde and phosphorous acid to obtain a methylatedMannich base MPV. The structure was characterized by IR and HNMR. In addition,the corrosion inhibition performance and mechanism of MPVE are analyzed by static weightlessness test,electrochemical method and SEM. The experimental results show that,in the static weight loss test,when the MPVE dosage is 600 mg/L,the corrosion rate is 0.062 mm/a,which is lower than the oil and gas industry standard 0.076 mm/a.As the amount of MPVE increases,the polarization curve shows a tendency to shift to the cathode,and the overall shift trend is less than 85mV,indicating that MPVE is mainly a mixed corrosion inhibitor that mainly suppresses the cathode reaction.It can be seen from the results of energy spectrum test that the new nitrogen, sulfur and phosphorus elements appear on the surface of the steel sheet with phosphine methylated Mannach base inhibitor compared with that of the blank steel sheet, which confirms the theory of the adsorption of lone electrons in heteroatoms on the metal surface, which can inhibit or slow down the corrosion.