四希夫碱-双曼尼希碱的合成及酸化缓蚀性能

SYNTHESIS OF FOUR SCHIFF BASE-DOUBLE MANNICH BASE AND ITS ACIDIFICATION AND CIORROSION INHIBITION

以水杨醛、二乙烯三胺、丙酮和甲醛为原料,通过Schiff反应合成希夫碱中间体(SBI),再通过Mannich反应合成了一种四希夫碱-双曼尼希碱(FSDM),对其结构进行红外表征。通过原子吸收分光光度法探究缓蚀剂在质量分数为15%盐酸溶液中缓蚀效果随时间的变化,结果表明SBI的缓蚀效果随时间变化不明显,而FSDM的缓蚀效果随时间增加而增加;通过电化学方法评价合成产物的缓蚀性能,在低浓度下FSDM的缓蚀效果要优于SBI,高浓度下无明显差异。室温下,浓度为100mg/L时,FSDM的缓蚀率为58%,SBI的缓蚀率为52%;浓度为1000mg/L时FSDM的缓蚀率为93%,SBI的缓蚀率为95%。通过原子力显微镜观察钢片腐蚀形貌,并探究缓蚀剂在钢片表面吸附情况;最后通过量子化学计算分析其缓蚀机理。

Schiff base intermediate (SBI)was synthesized by Schiff reaction with salicylaldehyde,di- ethylenetriamine,acetone and formaldehyde.Then,a Four Schiff base-double Mannich base (FSDM) was synthesized by Mannich reaction,whose structure is characterized by FTIR spectroscopic meth- ods.In order to test the inhibition effect of N80 steel in 15% hydrochloric acid,this paper used atomic absorption spectrophotometry.The results showed that the corrosion inhibition of SBI had no remark- able change with time,while the corrosion inhibition of FSDM increased with with time;the corrosion inhibition of the synthesized products was evaluated by electrochemical methods,and the results showed that the corrosion inhibition effect of FSDM was better than that of SBI at their low concen- tration,while it showed that there were no obvious differences at their high concentration.At room temperature,the inhibition rate of FSDM was 58% and SBI was 52% when the concentration was 100 mg/L;the inhibition rate of FSDM was 93% and SBI was 95% at the concentration of 1000mg/L. The corrosion morphology of the N80 steel was observed by AFM,and the adsorption of corrosion in- hibitor on the steel surface was explored by Langmuir adsorption curve.Finally,the mechanism of corrosion inhibition was further analyzed by quantum chemistry caIculation.