三种喹啉类衍生物的毒性预测及其对碳钢的缓蚀作用

Toxicity Estimation and Inhibition Performance Research on Mild Steel of Three Quinoline Derivatives in 1M Hydrochloric Acid

目的探究喹啉、5-苯并喹啉和8-羟基-5-苯并喹啉的健康毒性和生态毒性,以及这三种喹啉类衍生物对碳钢在1 mol/L HCl溶液中的防腐性能。方法采用毒性预测软件T.E.S.T对这三种物质进行毒性预测,筛选出环境友好型缓蚀剂。通过动电位极化曲线方法测定室温下喹啉、5-苯并喹啉和8-羟基-5-苯并喹啉对碳钢的缓蚀性能并比较缓蚀效果。根据吸附等温模型对缓蚀机理进行初步探讨。结果毒性计算表明,5-苯并喹啉没有致畸变性(Ames试验)和发育毒性,小鼠经口毒性LD50在第五级。8-羟基-5-苯并喹啉有致畸变性但无发育毒性,而喹啉存在致畸变性和发育毒性。通过动电位极化曲线测试发现,5-苯并喹啉和8-羟基-5-苯并喹啉对碳钢在1 mol/L HCl溶液中具有优异的缓蚀性能(在1 mmol/L浓度下,ηp(5-苯并喹啉)=94.74%,ηp(8-羟基-5-苯并喹啉)=98.06%)。喹啉的缓蚀效果在1 mmol/L处接近饱和,缓蚀效率仅为85%左右。从自腐蚀电位的移动判断,三种缓蚀剂均属于混合型缓蚀剂。吸附行为研究表明,喹啉、5-苯并喹啉和8-羟基-5-苯并喹啉在碳钢表面的吸附均符合Langmuir吸附,且为物理化学混合吸附。结论 5-苯并喹啉是一种环境友好型缓蚀剂。5-苯并喹啉和8-羟基-5-苯并喹啉对碳钢在1 mol/L HCl溶液中的抗腐蚀性能明显优于喹啉,这是由于苄基和羟基使得缓蚀剂分子在金属表面的化学吸附更加稳定,形成了致密的保护膜,有效减小了碳钢的腐蚀。

The work aims to study health toxicity and ecotoxicity of quinoline,5-benzylquinoline and 8-hydroxy-5-benzylquinoline,and their corrosion inhibition performance on mild steel in 1 mol/L HCl.The T.E.S.T software was utilized to estimate toxicity of the three quinoline derivatives and select environment-friendly inhibitors.Meanwhile,potentiodynamic polarization curve was used to investigate and further compare inhibition behavior of these inhibitors.In addition,corrosion inhibition mechanism was preliminarily explained based upon adsorption isothermal model.Toxicity calculations showed that 5-benzylquinoline had no mutagenicity(Ames test)and developmental toxicity,oral rat LD50 was at level 5.8-hydroxy-5-benzylquinoline;8-hydroxy-5-benzylquinoline had mutagenicity but no developmental toxicity;and quinoline had both mutagenicity and developmental toxicity.According to potentiodynamic polarization curve,5-benzylquinoline and 8-hydroxy-5-benzylquinoline exhibited excellent inhibition performance on mild steel in 1 mol/L HCl(ηp(5-benzylquinoline)=94.74%andηp(8-hydroxy-5-benzylquinoline)=98.06%at 1 mmol/L concentration).However,the inhibition performance of quinoline was nearly saturated at 1 mmol/L concentration since inhibition efficiency was nearly 85%.According to movement of self-corrosion potential,three inhibitors were all mixed-type inhibitors.Furthermore,adsorption of these inhibitors on mild steel could be fitted ideally by Langmuir adsorption model,which belonged to mixed physical chemical adsorption.5-benzylquinoline is an environment-friendly inhibitor.Inhibition performance of 5-benzylquinoline and 8-hydroxy-5-benzylquinoline be obviously superior to that of quinoline,which can be explained that benzyl and hydroxy groups enhance stability of inhibitor molecule chemical adsorption on metal surface,a dense protective film takes shape and effectively reduces corrosion of mild steel.