乌洛托品季铵盐缓蚀剂的合成与复配研究

以乌洛托品、溴己烷为主要原料,甲醇为溶剂,合成了一种乌洛托品季铵盐缓蚀剂,采用失重法研究了季铵盐缓蚀剂在15%(质量分数)HCl溶液中的缓蚀性能及复配性能,并采用量子化学计算对缓蚀剂机理进行分析,通过红外光谱、SEM对腐蚀后表面进行分析。结果表明,季铵盐缓蚀剂具有良好的缓蚀性能,在15%HCl、90℃下,加量0.5%(质量分数)时,缓蚀率达98.41%,并且与聚乙二醇、KI、丙炔醇复配后协同增效效果较好;量子化学计算表明该季铵盐缓蚀剂分子活性主要分布在分子环上,与乌洛托品相比具有更小的能隙,在Fe表面也具有更大吸附能,因此乌洛托品季铵盐活性更高。表面分析实验进一步验证了该缓蚀剂分子在QT-800钢片表面形成一层吸附膜。

Preparation of Urotropine Quaternary Ammonium Salt and Its Complex as Corrosion Inhibitor

A new type of urotropine quaternary ammonium salt as corrosion inhibitor was synthesized through nucleophilic reaction with urotropine and bromohexane as raw materials,while methanol as solvent.Then,the corrosion inhibition effect of quaternary ammonium salt for QT-800 steel in 15%(mass fraction)HCl solution was assessed by mass loss measurements,IR spectrometer and SEM.The mechanism of corrosion inhibition was studied by quantum chemical density functional theory.The results indicated that the quaternary ammonium salt has good corrosion inhibition performance,when urotropine quaternary ammonium salt of 0.5%(mass fraction)was added into 15%HCl solution at 90℃,the inhibition efficiency for QT-800 steel could reach up to 98.41%.The complexes of the urotropine quaternary ammonium salt with polyethylene glycol,potassium iodide and propynol were prepared respectively,and they all showed good performance in corrosion inhibition.Quantum chemical parameters indicates that the chemical activity of the urotropine quaternary ammonium salt is mainly distributed on the molecular ring,which has a smaller energy gap than the urotropine,and a larger adsorption energy on the iron surface.Therefore,the reactivity of urotropine quaternary ammonium salt is higher than that of urotropine.The results of IR spectrum and SEM analysis reveal that the urotropine quaternary ammonium salt molecules could adsorb on the surface of QT-800 steel during the corrosion test in HCl solution.