节点文献
含咪唑杂环的长链烷基双季铵盐的合成及其特性研究
Synthesis of Dodecane Alkyl Metronidazole Bisquats and Its Speciality against Microbe Induced Corrosion
【作者】 黄金营;
【导师】 郑家燊;
【作者基本信息】 华中科技大学 , 材料科学与工程, 2005, 博士
【摘要】 本文分别以2,2-二氯二乙醚和环氧氯丙烷为连接剂,通过对1-羟乙基-2-甲基-5-硝基咪唑的季铵化,首次合成了两种含咪唑杂环的长链烷基双季铵盐化合物:二氯化N-(1-羟乙基-2-甲基-5-硝基咪唑基)-N-(十二烷基二甲基) -3-氧杂-1,5-戊二铵(简称MDOPD)和二氯化N-(1-羟乙基-2-甲基-5-硝基咪唑基)-N-(十二烷基二甲基)-2-羟基-1,3-丙二铵(简称MDHTD),进行了分子结构的红外光谱表征和合成条件的优化; 重点对其缓蚀和抑菌特性进行了深入系统的研究,为油田微生物腐蚀的防治提供理论依据和技术支持。利用静态失重、动电位扫描极化曲线、交流阻抗(EIS)、X-射线衍射(XRD)和扫描电子显微镜(SEM)等多种分析测试方法,研究了含咪唑杂环的双季铵盐化合物的缓蚀吸附规律,探讨了其缓蚀作用机制。在模拟油田水介质中:含咪唑杂环双季铵盐化合物的较强缓蚀吸附性能与其分子中含有二氮五元杂环、杂环上的季氮原子、长链烷基季氮原子、醚氧基或羟基等多个活性吸附中心有关。热力学和动力学模型的拟合结果显示,含羟基的MDHTD 较含醚氧基的MDOPD 具有更强的吸附缓蚀性能。在含硫酸盐还原菌(SRB)的培养基介质中:含咪唑杂环的双季铵盐化合物MDHTD 对碳钢腐蚀过程的阳极反应有显著的抑制作用,且存在浓度极值现象,这与MDHTD 的分子结构和吸附特性有关; MDHTD 的吸附和缓蚀作用不受SRB 生长特性的影响,在普通SRB 菌和和活性更强的碱性变异菌介质中,对碳钢都有显著的保护作用,且优于传统的缓蚀杀菌剂十二烷基二甲基苄基氯化铵(简称“1227”); 对J55和N80 钢的腐蚀都有明显的抑制效果。杀菌性能评价实验结果表明:MDHTD 对普通SRB 菌、碱性变异SRB 菌、生物膜中SRB 菌和腐生菌(TGB)的灭菌活性都高于传统杀菌剂1227,能够在较低浓度下杀灭铁细菌(IB)。采用原子力显微镜(AFM)、电子探针(EPMA)、X-射线光电子能谱(XPS)和交流阻抗(EIS)等方法系统地研究了MDHTD 对生物膜腐蚀的抑制机理及模型。在含SRB 菌介质中,MDHTD 通过在碳钢表面吸附并形成有机保护膜,对不同生长周期SRB 生物膜下碳钢的腐蚀都具有良好的保护效果; 对SRB 代谢过程的抑制使SO42-离子中的六价硫被还原并与Fe2+生成多种过渡价态铁硫化合物在碳钢表面沉积的机会极大地降低; 能够使SRB 生物膜与碳钢金属表面的结合力下降,并通过对生物膜的剥离作用和在金属表面活性点的吸附使腐蚀反应的电荷转移电阻升高,能够抑制侵蚀性的Cl-离子等通过多孔生物膜表面渗透而造成的侵蚀。
【Abstract】 In this paper, two new germicide-inhibitor of bisquats which were named N-Metronidazole-N-( Dodecane Dimethyl )-3-Oxa -1,5-Pentanedilammonium Dichloride ( MDOPD ) and N-Metronidazole-N-( Dodecane Dimethyl )-2-Hydroxy-1,3-Thirddilammonium Dichloride ( MDHTD ) were successfully synthesized for the first time with metronidazole as matrix and 2,2-Dichloroethyl ether 1-Chloro-2-2(β-chloroethoxy) ethane or α-epichlorohydrin as link agent, respectively. The molecule structures of bisquats were illustrated by IR spectrum and the synthesis conditions were optimized in detail such as solvent, temperature and reaction time. Weight loss measurement, Potentiodynamic polarization curves, Electrochemical Impedance Spectroscopy (EIS), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to investigate the corrosion inhibiting performance of MDOPD and MDHTD in simulated oilfield water. MDOPD and MDHTD were found to having good water solubility and prominent corrosion inhibiting performance, temperature had little effect on inhibitory efficiency of MDOPD and MDHTD in the studied temperature range at higher inhibitor concentrations. The corrosion mechanism of carbon steel in simulated oilfield water containing MDOPD or MDHTD was analysed with thermodynamic and kinetics models, MDHTD and MDOPD possessed several nitrogen atoms as adsorption centre which had much active energy with metal surface and MDHTD had more effectively protection function. The anode reaction of corrosion course was restrained on account of the addition of MDHTD in culture medium inoculated SRB, phenomenon of maximum concentration effect was found while concentration of MDHTD was increased. The anode polarization curves revealed three different segments and temparature had little effect on the adsorption of MDHTD on Q235 steel. Corrosion of Q235 steels in culture medium inoculated SRB was effectively restrained by the sterilization capability of MDHTD against SRB in medium and the adsorption on Q235 steel surface. And that MDHTD had more excellent protective effect than 1227 in culture medium inoculated original SRB or drug-fast SRB. The sterilization effect of the bisquats was assessed according to API RP-38 standard. MDHTD exhibited better inhibitive effect on drug-fast SRB and original bacteria not only in culture medium but also in biofilm. Besides, the two bactericides also showed excellent inhibitive performance against IB at low concentration. The inactivation curves indicate that MDHTD has more effective antibacterial performance than “1227”due to the functional group in molecule structure of MDHTD. At the same time, MDHTD has effect on the formation and growth of TGB biofilm and some TGB has distinct sensitivity to MDHTD. Sensitivity of SRB biofilms to MDHTD and corrosion inhibiting effect of MDHTD for metal under biofilms were further investigated using Atomic Force Microscopy (AFM)、Electron Probe Micro-Analysis (EPMA) 、X-ray Photoelectron Spectroscopy (XPS) and EIS. Results revealed that MDHTD had better protective effect than “1227”on Q235、J55、N80 steel in culture medium inoculated SRB by forming adsorption film segregating chlorine ion on metal surface and corrosion under various thickness biofilm was also effectively restrained by MDHTD. Metabolite and FeSx by SRB greatly decreased owing to impact of MDHTD. The binding force between metal surface and biofilm was reduced by peeling off effect of MDHTD and charge transfer resistance of corrosion reaction accordingly increased, so corrosion induced by corrosive chlorine ion penetrating the porous biofilm was commendably restrained. AFM、EPMA and EIS were initially used to research the mechanism of MDHTD against TGB in culture medium. Results showed that MDHTD could form integrated and compact adsorption film on Q235 steel in culture medium, it was difficult for metabolite by TGB to deposit on the carbon steel surface and phosphorus was enriched on biofilm surface. Furthermore, corrosion caused by oxygen concentration difference was effectively inhibitted by penetration, peeling off and adsorption effect of MDHTD. In a word, Microbiologically Influenced Corrosion in oilfield system could be restrained by addition o f MDHTD on account of its action on the self-existent activation effect by microbe.