新型双子表面活性剂在H2S和CO2盐水溶液中对碳钢的缓蚀性能

合成了一系列含有羟基的双子表面活性剂:1,3-双(十二烷基二甲基氯化铵)-2-丙醇(12-3OH-12),1,3-双(十四烷基二甲基氯化铵)-2-丙醇(14-3OH-14),1,3-双(十六烷基二甲基氯化铵)-2-丙醇(16-3OH-16)和1,3-双(十八烷基二甲基氯化铵)-2-丙醇(18-3OH-18).采用静态失重法、极化曲线和交流阻抗技术研究了其在H2S/CO2腐蚀环境中对L360钢的缓蚀作用.结果表明,三种研究方法取得的结论是一致的,缓蚀效果为14-3OH-14>12-3OH-12>16-3OH-16>18-3OH-18.其中,12-3OH-12和14-3OH-14都表现出很好的缓蚀效果,在35mg·L-1的较低浓度下缓蚀率就达95%以上.极化曲线测试结果表明n-3OH-n(n=12,14,16,18)型双子表面活性剂是一种以阳极抑制为主的混合型缓蚀剂.除n=18外,其它三种双子表面活性剂n-3OH-n(n=12,14,16)在L360钢表面的吸附服从朗缪尔等温线,并且属于物理和化学混合吸附.提出了一个用来解释双子表面活性剂在H2S/CO2溶液中缓蚀机理的吸附模型.

Corrosion Inhibition Performance of Carbon Steel in Brine Solution Containing H2 S and CO2 by Novel Gemini Surfactants

A series of novel gemini surfactants containing hydroxyl group have been synthesized including 1,3-bis(dodecyl dimethyl ammonium chloride)-2-propanol,1,3-bis(myristyl dimethyl ammonium chloride)-2-propanol,1,3-bis(hexadecyl dimethyl ammonium chloride)-2-propanol,and 1,3-bis(octadecyl dimethyl ammonium chloride)-2-propanol,designated as n-3OH-n(n=12,14,16,18,respectively).The corrosion inhibition for carbon steel in brine solution containing H 2 S and CO 2 was investigated using weight loss method,potentiodynamic polarization,and electrochemical impedance spectroscopy(EIS).The results showed that the inhibition efficiencies(IEs)obtained from all of the methods employed demonstrated a clear trend,with the IEs of the gemini surfactants ranked as 14-3OH-14>12-3OH-12> 16-3OH-16>18-3OH-18.Among them,14-3OH-14 and 12-3OH-12 acted as excellent corrosion inhibitors with IE values greater than 95%at an additive concentration of 35 mg·L -1 .Potentiodynamic polarization curves clearly revealed that the gemini surfactants are mixed-type inhibitors which preferentially inhibit the anodic corrosion process.Adsorption of the synthesized gemini surfactants n-3OH-n(n=12,14,16)onto a carbon steel surface obeys the Langmuir adsorption isotherm and they exhibit a mixed physical and chemical adsorption.An adsorption model was proposed to elucidate the inhibition mechanism of gemini surfactants.