环糊精修饰丙烯酰胺聚合物对L485钢的腐蚀行为研究

发布时间：2018-03-26 14:54

本文选题：环糊精　切入点：丙烯酰胺　出处：《西南石油大学》2015年硕士论文

【摘要】：在石油天然气开发过程中,油田管道与设备的腐蚀普遍存在,因此研究金属的腐蚀与防护对石油工业的发展具有重要意义。缓蚀剂由于具有加量少、见效快等优点而应用最为广泛。本文运用电化学阻抗谱(EIS、Tafel极化曲线、扫描电子显微镜技术(SEM)及分子动力学模拟(MD)研究了环糊精修饰丙烯酰胺聚合物(HCMPAM)在0.5mol/LH2SO4溶液中对L485钢的腐蚀行为。同时分析了HCMPAM在L485钢表面的吸附模型和热力学、动力学参数,为HCMPAM作为缓蚀剂在实际中的应用及可行性提供理论依据。论文的主要研究内容如下： (1)本文利用EIS、Tafel曲线研究了在不同物质浓度、介质温度条件下,p-环糊精(p-CD)和HCMPAM在0.5mol/L H2SO4容液中对L485钢的腐蚀行为。结果表明：加入β-CD和HCMPAM后,L485钢在H2S04中发生腐蚀的电荷转移电阻Rct增大,双电层电容Q1降低,腐蚀电流密度icorr减小,L485钢在H2S04中的腐蚀减弱,且HCMPAM能L485钢表面吸附形成保护膜而并没有改变钢的腐蚀机理。另外,HCMPAM表现为混合型缓蚀剂,其缓蚀效率随着浓度的增大而增加,随着温度的升高而降低。其中p-CD和HCMPAM缓蚀效率顺序为:HCMPAMβ-CD,β-CD对L485钢几乎不表现出缓蚀效果。 (2)利用Tafel曲线的icorr数据分析了HCMPAM在L485钢表面的吸附模型及相关动力学、热力学参数。结果表明：L485钢在H2S04中的腐蚀为吸热过程,因此温度的升高会加剧L485钢的腐蚀。HCMPAM的加入,使L485钢在H2S04中发生腐蚀反应所需的活化能Ea和活化焓△H*增加,从而增大了L485钢发生溶解腐蚀的阻力。同时HCMPAM在L485钢表面的吸附符合Langmuir吸附模型,HCMPAM分子通过化学作用自发的吸附在L485钢表面。另外,HCMPAM在L485钢表面的吸附是放热过程,因此升温会减弱HCMPAM在L485钢表面的吸附。 (3)SEM和EDS分析结果表明：相比空白溶液而言,当加入HCMPAM时,L485钢表面表现为均匀腐蚀,无点蚀发生；另外,从EDS分析结果可以看出,加入HCMPAM后,L485钢表面腐蚀产物中Fe的含量明显升高,O的含量明显降低,且检测到N原子的存在,因此HCMPAM分子能吸附在L485钢表面形成保护膜从而阻碍H2SO4介质与L485钢表面接触。 (4)MD研究表明：HCMPAM能较快且平行地吸附在Fe表面,且HCMPAM分子通过分子中的氮、氧等原子与Fe原子的成键和非键共同作用吸附在Fe表面。
[Abstract]:In the course of oil and gas development, corrosion of pipelines and equipments in oil fields is widespread, so it is important to study corrosion and protection of metals for the development of petroleum industry. In this paper, electrochemical impedance spectroscopy (EIS) and Tafel polarization curve are used. The corrosion behavior of cyclodextrin modified acrylamide polymer (HCMPAM) on L485 steel in 0.5mol/LH2SO4 solution was studied by scanning electron microscopy (SEM) and molecular dynamics simulation (MD). The adsorption model, thermodynamics and kinetic parameters of HCMPAM on L485 steel surface were also analyzed. To provide theoretical basis for the application and feasibility of HCMPAM as corrosion inhibitor in practice. The main contents of this paper are as follows:. 1) in this paper, the concentration of different substances was studied by using the EIS-Tafel curve. The corrosion behavior of p-CD and HCMPAM on L485 steel in 0.5mol/L H2SO4 solution at medium temperature. The results show that the charge transfer resistance (Rct) of L485 steel corroded in H2S04 increases with the addition of 尾 -CD and HCMPAM, and the double layer capacitance Q1 decreases with the addition of 尾 -CD and HCMPAM. The corrosion current density (icorr) decreases the corrosion of L485 steel in H2S04, and the corrosion inhibition efficiency increases with the increase of the concentration of L485 steel, and the corrosion mechanism of L485 steel is not changed by the adsorption of the protective film on the surface of HCMPAM, and the corrosion inhibition efficiency of L485 steel increases with the increase of the concentration. The corrosion inhibition efficiency of p-CD and HCMPAM is in the order of: HCMPAM 尾 -CD-CD, and 尾 -CD has little inhibition effect on L485 steel. Using the icorr data of Tafel curve, the adsorption model of HCMPAM on the surface of L485 steel and the related kinetic and thermodynamic parameters are analyzed. The results show that the corrosion of HCMPAM in H2S04 is an endothermic process, so the increase of temperature will aggravate the corrosion of L485 steel. The activation energy (EA) and activation enthalpy (H *) required for the corrosion reaction of L485 steel in H2S04 were increased. Meanwhile, the adsorption of HCMPAM on L485 steel surface accords with the Langmuir adsorption model. The adsorption of HCMPAM molecules on L485 steel surface spontaneously by chemical action. In addition, the adsorption of HCMPAM on L485 steel surface is exothermic, and the adsorption of HCMPAM on L485 steel surface is an exothermic process, and the adsorption of HCMPAM on L485 steel surface is an exothermic process. Therefore, the adsorption of HCMPAM on the surface of L485 steel will be weakened by heating. The results of SEM and EDS analysis show that compared with the blank solution, the surface of L485 steel is uniformly corroded and no pitting corrosion occurs when HCMPAM is added, in addition, it can be seen from the results of EDS analysis, After adding HCMPAM, the content of Fe in the corrosion products of L485 steel obviously increased and the content of O decreased obviously, and the presence of N atoms was detected. Therefore, HCMPAM molecules can be adsorbed on the surface of L485 steel to form a protective film, which hinders the contact between H2SO4 medium and the surface of L485 steel. The results show that HCMPAM molecules can be adsorbed on Fe surface quickly and parallel, and HCMPAM molecules are adsorbed on Fe surface by the bonding and non-bonding interaction of atoms such as nitrogen and oxygen with Fe atoms.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE980;O631.3

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