新型喹啉季铵盐酸化缓蚀剂氯化苯甲酰甲基喹啉(PCQ)的合成及缓蚀性能

Synthesis and Acidification Corrosion Inhibition Performance of a Novel Quinoline Quaternary Ammonium Salt — Phenacyl Quinoline Chloride(PCQ)

以氯化苄、2-氯代苯乙酮、喹啉为原料,通过季铵化反应合成了氯化苄基喹啉(BQC)以及新型的氯化苯甲酰甲基喹啉(PCQ)两种季铵盐型缓蚀剂,其中PCQ为首次合成。PCQ的制备条件为:以丙酮为溶剂,在75℃水浴条件下回流20 h,采用无水乙醇对产品进行重结晶。采用元素分析、核磁共振和红外光谱等手段对两种季铵盐产物的结构进行了表征,并在90℃、15%盐酸条件下通过静态失重法对两种季铵盐单独使用及分别与丙炔醇、碘化钾复配使用的缓蚀效果进行了对比评价。1. 00%添加量的BQC、PCQ对N80钢的缓蚀率分别为82. 17%、94. 25%; PCQ与丙炔醇的加量分别为0. 50%时的复配缓蚀体系可使N80钢的缓蚀率达到99. 88%。BQC与PCQ在N80钢表面的吸附行为均为自发的放热过程且均符合Langmuir吸附等温式。在90℃时,BQC和PCQ的吸附平衡常数kads分别为483. 10 L/mol和1 092. 75 L/mol,吸附吉布斯自由能分别为-30. 77 kJ/mol、-33. 24 kJ/mol,说明两种季铵盐在N80钢表面的吸附均以化学吸附为主。

In this contribution,we present the preparation of a novel (firstly originated) corrosion inhibitor,i.e.phenacyl quinoline chloride (PCQ),and the comparative analyses upon the corrosion inhibition performances between PCQ and benzyl quinoline chloride (BQC,a commonly used corrosion inhibitor for acidizing).The PCQ was synthesized through the quaternarization reaction of quinoline,benzyl chloride and 2-chloroacetophenone under the condition of 75 ℃ and 20 h reflux,by using acetone as solvent and ethanol as recrystallizing agent.The chemical structures of PCQ and BQC were characterized by elemental analysis,NMR and IR.The corrosion inhibition performances of the two quaternary ammonium salts (use in isolation,use in combination with propargyl alcohol(PA),and use in combination with potassium iodide) were evaluated by static weight loss method in 15% hydrochloric acid at 90 ℃.Our experiments show that the inhibition efficiency of BQC and PCQ are 82.17% and 94.25%,respectively,under the adding amount of 1.00%.The inhibition efficiency of the combination of 0.50% PCQ+0.50% propargyl alcohol is 99.88%.The adsorption behaviors of BQC and PCQ on the surface of N80 steel coincide well with Langmuir adsorption isotherm.Moreover,the adsorption equilibrium constants k ads of BQC and PCQ are 483.10 L/mol and 1 092.75 L/mol,respectively,and the Gibbs free energy change values are -30.77 kJ/mol and -33.24 kJ/mol with respect to BQC and PCQ,indicating the chemical-adsorption-dominated,also spon-taneous and exothermic adsorption processes of these two quaternary ammonium salts onto the N80 steel surface.