多吸附位点席夫碱缓蚀剂的合成及缓蚀效果

Synthesis and performance evaluation of a new type of Schiff base corrosion inhibitor with multiple reaction centers for P110 steel

以4-三氟甲基苯甲醛与乙二胺为原料,经Schiff反应合成了席夫碱化合物(BEA),反应条件:反应温度为65℃,n(乙二胺)∶n(4-三氟甲基苯甲醛)=5∶1,反应时间为6 h;BEA与均苯三甲酰氯经酰胺化反应合成了多吸附位点席夫碱缓蚀剂(BTA),反应条件:反应温度为50℃,n(BEA)∶n(均苯三甲酰氯)=3.3∶1,反应时间为8 h。采用静态挂片失重法、电化学法和扫描电子显微镜(SEM)研究BEA和BTA对P110钢在1 mol/L盐酸中的缓蚀性能。失重法研究表明,当缓蚀剂质量浓度为200 mg/L时,BTA缓蚀率达99.39%,BEA的缓蚀率仅94.29%;等温吸附行为研究结果表明,缓蚀剂分子能自发地吸附于P110钢表面,满足Langmuir吸附模型;电化学法研究结果表明,BTA属于阳极控制型,在金属表面形成保护性膜,能有效抑制金属腐蚀。因此,多吸附位点缓蚀剂BTA缓蚀性能优于BEA。

BEA is prepared from 4-（ trifluoromethyl） benzaldehyde and ethanediamine through Schiff reaction at65℃ for 6 hours with 5 ∶ 1 molar ratio of ethanediamine and 4-（ trifluoromethyl） benzaldehyde. Then,BEA and 1,3,5-benzenetricarbonyl trichloride are used to synthesize a new corrosion inhibitor with multiple reaction centers,named as BTA,at 50℃ for 8 hours with 3. 3∶ 1 molar ratio of BEA and 1,3,5-benzenetricarbonyl trichloride. Weight loss method,potentiodynamic polarization curves,electrochemical impedance spectroscopy and scanning electron microscopy（ SEM）are used to study the inhibition performance of BTA for P110 steel in 1. 0 mol / L HCl. The results of weight loss method show that BTA has more excellent inhibition efficiency than BEA. When the concentration is 200 mg / L,the inhibition efficiency can reach 99. 39%,while BEA is only 94. 29%. The isothermal adsorption result demonstrates that BTA molecules can spontaneously be adsorbed on P110 steel surface and the adsorption process follows Langmuir adsorption model. The results of electrochemical method indicate that BTA is an anodic type inhibitor,which can form protective layers on P110 steel surface and effectively inhibit its corrosion. All the results show that BTA is superior to BEA.