液压支架浓缩液用咪唑啉缓蚀剂的合成与性能研究

Synthesis and properties of imidazoline corrosion inhibitor for hydraulic support concentrate

为了有效缓解液压支架的滤芯和立柱锈蚀现象,以二甲苯为溶剂和携水剂,采用酰化-环化反应在癸二酸、L-谷氨酸的基础上引入了五元氮杂环咪唑啉基团,采用氯乙酸钠为季铵盐化试剂增强水溶性,合成了2种缓蚀性能优良的液压支架浓缩液用癸二酸双环咪唑啉季铵盐GM-1和L-谷氨酸双环咪唑啉季铵盐LM-1缓蚀剂,通过红外光谱对其进行了结构确认,通过腐蚀失重、水接触角、电化学、量子化学方法研究了2种添加剂在质量浓度为330 mg/L的NaCl腐蚀介质中对HT300灰口铸铁的缓蚀性能,探讨了2种添加剂分子在HT300灰口铸铁表面的吸附作用方式和缓蚀机理。研究结果表明:2种添加剂均对质量浓度为330 mg/L的NaCl腐蚀介质中浸泡的HT300灰口铸铁的缓蚀性能良好,当加入质量分数为0.5%的添加剂时,GM-1和LM-1的缓蚀率分别达到了95.89%和85.79%,电化学表明2种添加剂均为阳极型缓蚀剂,抑制了电荷在石墨电极和灰口铸铁之间的转移,添加剂在铸铁表面的吸附方式满足Langmuir单分子层吸附,吉布斯自由能分别为-35.361 kJ/mol和-31.093 kJ/mol,表明是自发的物理吸附和化学吸附过程,且以化学吸附为主。当分别加入质量分数为0.5%的添加剂时,GM-1和LM-1浸泡后的HT300灰口铸铁表面水接触角分别达到了86.24°和82.34°,表明添加剂分子在HT300灰口铸铁表面形成了疏水性薄膜,隔绝了Cl-的侵蚀。量子化学表明2种添加剂通过配位键和反馈键形成吸附膜,GM相较于LM更容易给出电子金属的空3d轨道形成了配位键,吸附需要的能垒更小,因此更容易在HT300灰口铸铁表面发生吸附。

In order to effectively alleviate the corrosion of the filter element and column of the hydraulic support,five-membered nitrogen heterocyclic imidazoline group was introduced on the basis of sebacic acid and L-glutamic acid by acylation-cyclization reaction,and xylene was used as solvent and water-carrying agent.Two kinds of corrosion inhibitor of bicyclic imidazoline quaternary ammonium sebacate GM-1 and L-glutamic acid bicyclic imidazoline quaternary ammonium salt LM-1 were synthesized with excellent corrosion inhibition performance for hydraulic support concentrate.The water solubility is enhanced by using sodium chloroacetate as a quaternary ammonium salting agent.Its structure was confirmed by infrared spectroscopy.The corrosion inhibition performance of two additives on HT300 gray cast iron in 330 mg/L NaCl corrosion medium was studied by corrosion weight loss,water contact angle,electrochemical and quantum chemical methods.Adsorption mode and corrosion inhibition mechanism of two additive molecules on the surface of HT300 gray cast iron.The research results show that both additives have good corrosion inhibition performance on HT300 gray cast iron immersed in 330 mg/L NaCl corrosive medium.The corrosion rate reached 95.89%and 85.79%respectively.Electrochemistry shows that both addit are anodic corrosion inhibitors and inhibit the transfer of charge between the graphite electrode and gray cast iron.The adsorption mode of additives on the surface of cast iron satisfies the Langmuir monolayer adsorption,and the Gibbs free energies are-35.361 kJ/mol and-31.093 kJ/mol respectively.It shows that the adsorption is a spontaneous physical adsorption and chemical adsorption process,and chemical adsorption is the main.When adding additives with a mass concentration of 0.5%,the water contact angles on the surface of HT300 gray cast iron soaked in GM-1 and LM-1 reached 86.24°and 82.34°,respectively,indicating that the corrosion of Cl-was isolated through the presence of additive molecules in the hydrophobic film is formed on the surface of HT300 gray cast iron.Quantum chemistry shows that adsorption films are formed through coordination and feedback bonds.Compared with LM,GM is easier to adsorb on the surface of HT300 gray cast iron because the empty 3d orbital of metal is easier to give electrons to form coordination bonds and the energy barrier required for adsorption is smaller.