4-苯基氨基硫脲在盐酸介质中对Q235钢的缓蚀性能  

Inhibition Performance of 4-Phenylthiosemicarbazide for Q235 Steel in HCl Solution

作　　者：孟玥[1] 宁文博[1] 徐斌[1] 杨文忠[1] 刘学忠[2] 张凤友[2] 

机构地区：[1]南京工业大学化学与分子工程学院,南京210009 [2]中国电子工程设计院,北京100142

出　　处：《表面技术》2016年第7期68-73,共6页Surface Technology

基　　金：国家水专项基金资助项目(2013ZX07210001);2015年江苏省大学生创新创业训练计划重点项目(201510291010Z);国家开发投资公司基金资助项目(DZY150001KYF3);中国水利水电科学研究院基金资助项目(20154209)~~

摘　　要：目的研究4-苯基氨基硫脲(4-PTC)对Q235钢在1mol/L HCl中的缓蚀作用。方法采用异硫氰酸苯酯和水合肼为原料,合成4-PTC。采用熔点分析、核磁共振氢谱和红外光谱等方法确定合成物质为目标产物4-苯基氨基硫脲。采用静态失重法、电化学极化曲线法、电化学阻抗谱法和扫描电子显微镜法,分析研究4-PTC的缓蚀性能。结果静态失重实验表明,当4-PTC浓度增加到1.0 mmol/L时,缓蚀效率达到85.9%,在Q235钢表面吸附符合Langmuir吸附等温式,形成单分子吸附层。计算得到吉布斯自由能为?35.60 k J/mol,说明缓蚀剂分子在Q235钢表面吸附同时存在物理吸附和化学吸附过程。动电位极化曲线表明,该缓蚀剂是以阴极型为主的混合型缓蚀剂,当4-PTC浓度增加到1.0 mmol/L时,缓蚀效率达到83.6%。电化学阻抗谱表明,随4-PTC浓度的增加,电荷转移电阻值增大,双电层电容值减小,金属腐蚀速率降低,缓蚀作用增强。当4-PTC浓度增加到1.0 mmol/L时,缓蚀效率达到84.7%。扫描电子显微镜表明,缓蚀剂分子能有效保护金属表面,抑制腐蚀。结论在盐酸介质中,4-PTC对Q235钢具有优良的缓蚀性能。Objective To investigate the inhibition performance of 4-Phenylthiosemicarbazide （4-PTC） for Q235 steel in 1mol/L HCl solution. Methods A new corrosion inhibitor, 4-PTC, was synthesized using phenyl isothiocyanate and hydrazine hydrate as raw materials. The synthesized compound was confirmed by melting point, 1H-NMR and IR methods. The corrosion troscopy and scanning electron microscope methods. Results The results of weight loss measurements showed that the inhibition efficiency of 4-PTC could reach up to 85.9% at the concentration of 1.0 mmol/L and the adsorption process obeyed the Langmuir adsorption isotherm, forming monolayer. The value of AGads was -35.60 kJ/mol, which indicated that the adsorption mechanism involved both chemisorption and physisorption. The potentiodynamic polarization plots showed that 4-PTC acted as a mixed type inhibitor and showed more pronounced influence in the cathodic polarization plots compared to that in the anodic plots. The inhibition efficiency of 4-PTC could reach up to 83.6% at the concentration of 1.0 mmol/L. Meanwhile, the electrochemical impedance showed that the charge transfer resistance increased with the increase of the 4-PTC concentration, while the value of double layer capacitance decreased. This phenomenon showed that the corrosion rate decreased and the inhibition efficiency increased. The inhibition efficiency of 4-PTC could reach up to 84.7% at the concentration of 1.0 mmol/L. The scanning electron microscope method showed that the 4-PTC had excellent inhibition behavior and could protect the Q235 steel. Conclusion 4-PTC showed good inhibition efficiency for Q235 steel in HCl solution.

关 键 词：4-苯基氨基硫脲 缓蚀剂 Q235钢 失重法 电化学测试 

分 类 号：TG174.42[金属学及工艺—金属表面处理]