氨基酸复配酸洗缓蚀剂的研究

目的氨基酸对环境无毒无害,生产成本低,可生物降解且水溶性较高,是一种极具发展潜力的新型绿色酸洗缓蚀剂。探究在盐酸介质中,氨基酸及复配缓蚀剂对Q235钢的缓蚀作用。方法采用失重法,利用电子分析天平精确称量浸入腐蚀介质前后金属试样的质量来确定金属的腐蚀速率。研究了L-半胱氨酸及其复配缓蚀剂在1 mol/L盐酸介质中对Q235钢的缓蚀性能,借助等温吸附模型对其缓蚀机理进行了探讨。结果单独使用L-半胱氨酸缓蚀效率较低。当质量浓度为800 mg/L时,L-半胱氨酸的缓蚀效率达到最大值,为65.57%。复配合成缓蚀剂能降低经济成本,并提高缓蚀效率。通过三元复配实验得出L-半光氨酸、KI和抗坏血酸的最佳复配比,当L-半胱氨酸、KI、抗坏血酸的质量浓度分别为20、30、250 mg/L时,其缓蚀效率可达96.37%,且成本较低,是较理想的复配缓蚀剂。复配缓蚀剂在Q235钢表面的吸附符合Langmuir吸附等温模型。结论在盐酸介质中,L-半胱氨酸三元复配缓蚀剂整体用量适中,价格合理,证明复配缓蚀剂是一种能够得到良好应用的绿色缓蚀剂。

Amino Acid Corrosion Inhibitor in Hydrochloric Acid

Objective Amino acids are cheap, innoxious, biodegradable and with a great potential for wide application. This work aimed to investigate the corrosion inhibition of Q235 steel in HCl medium by composite amino acid corrosion inhibitor. Methods In order to determine the corrosion rate of metals, the samples were weighed before and after the tests using an analytical balance with a precision of 0.1 mg. The corrosion inhibition performance of L-cysteine and its composite corrosion inhibitor for Q235 steel in 1 mol/L hydrochloric acid medium was analyzed by weight loss method, and the inhibition mechanism was discussed by isothermal adsorption model. Results The corrosion efficiency of L-cysteine was not high when used alone. The corrosion inhibition of the single inhibitor was 65.57% when the dosage was 800 mg/L. The ternary inhibitor could reduce the cost and improve the efficiency of corrosion inhibition. L-cysteine, KI and ascorbic acid were mixed together and the optimal mixture ratio was obtained. When the concentrations of L-cysteine, KI and ascorbic acid were 20 mg/L, 30 mg/L and 250 mg/L, respectively, the corrosion inhibition efficiency reached up to 96.37%. The composite corrosion inhibitor obeyed Langmuir adsorption isotherm on the surface of Q235 steel. Conclusion Composite corrosion inhibitor had good inhibitory effect for Q235 steel in HCl medium at reasonable dosage and cost, and is thus an environment-friendly green inhibitor with wide application prospect.