带锈表面的预处理及其匹配环氧涂层的应用研究
发布时间：2019-02-18 16:24
【摘要】：近年来,人们一直被涂装前金属表面带锈的问题所困扰。由于铁锈成分的复杂性与多样性,它不仅会影响涂层的附着力,还会影响涂层的耐腐蚀性,所以需要对表面锈层进行清除。而传统的除锈方法会造成环境污染,成本增加等问题,因此关于直接在锈层上涂装的方法成为了研究热点。以往的研究主要采用磷酸、单宁酸对锈层进行处理,其不足之处是不能渗入到多孔锈层的内部,并且酸量也很难控制。针对这些问题,本论文选择了具有高表面活性的全氟辛酸铵(PFOA)进行了研究,围绕其与锈层的作用开展了工作,研究内容和结果如下:(1)采用全氟辛酸铵溶液对带锈表面进行浸渍处理,对处理后的表面采用傅里叶变换红外光谱(FT-IR)、能谱仪(EDS)、扫描电子显微镜(SEM)、激光共聚焦扫描显微镜、接触角及电化学极化曲线等检测手段,对其结构、元素成分、表面微观形貌、润湿性及耐蚀性进行表征。结果表明,全氟辛酸铵溶液是具有较好扩散性和润湿性的中性溶液,能够渗入多孔的锈层到达基材表面,形成吸附膜,破坏锈层与基材的结合作用。此外,浓度为150g/L时的全氟辛酸铵溶液对带锈表面的处理是优于其它浓度的。(2)虽然全氟辛酸铵溶液的润湿性与渗透性很好,但对带锈表面的耐蚀性和粘结性提高不显著,同时考虑到硅烷偶联剂具有无污染、适用广泛、成膜效果好、对有机涂层粘结性能优异等优点,所以本论文将全氟辛酸铵溶液与硅烷偶联剂(KH550、KH560)相混合使二者产生协同作用,对带锈表面进行浸渍处理后,再对表面进行加热使其固化成膜,对制成的表面膜进行性能检测以确定最佳水解、固化工艺参数。检测结果表明:PFOA/KH550膜与PFOA/KH560膜表面都发生了聚合交联反应,且PFOA/KH550膜与基材表面结合的更强些;当KH550与PFOA的质量比为1:1,KH550的溶液浓度为10%,固化时间为1.5h,固化温度为150℃时所制得的表面膜与其它工艺下所制得的膜相比,厚度最大、对金属基体的包覆率最大、膜的封闭性最好、润湿性适中、耐蚀性显著提升;无论是在不同水解工艺下还是在不同固化工艺下,所制得的PFOA/KH550膜的各性能都要优于PFOA/KH560膜。(3)对带锈表面进行预处理的最终目的是与涂层相匹配,本论文研究了三类不同预处理后的表面(未经处理的带锈表面、经KH550/PFOA混合溶液处理的带锈表面、经KH560/PFOA混合溶液处理的带锈表面)与环氧有机涂层的匹配效果。研究结果表明:经KH550/PFOA溶液处理的表面涂层的各项机械性能是优于其它两类的;表面涂层在经过盐水浸泡62d后,只有KH550/PFOA溶液处理的表面涂层破坏最小,只产生微变色;涂层试样经拉拔试验后发现,经KH550/PFOA溶液处理的表面与环氧有机涂层的附着力要高于其它两种表面;而且其表面涂层的腐蚀电流密度与其它两种相比显著下降,因而具有最优的防腐效果。
[Abstract]:In recent years, people have been plagued by the problem of rust on the metal surface before painting. Because of the complexity and diversity of the rust component, it not only affects the adhesion of the coating, but also affects the corrosion resistance of the coating, so it is necessary to clean the surface rust layer. The traditional method of derusting can cause the problems of environmental pollution and cost, so the method of coating directly on the rust layer has become a hot spot. In the past, phosphoric acid and tannic acid are used to treat the rust layer, and the disadvantage is that it is not allowed to penetrate into the inside of the porous rust layer, and the amount of the acid is also difficult to control. In order to solve these problems, the paper chose the perfluorooctanoic acid solution (PFOA) with high surface activity, and carried out the work around it and the rust layer, and the contents and results were as follows: (1) The dipping treatment of the stainless steel surface was carried out by using the perfluorooctanoic acid solution. Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), laser confocal scanning microscope, contact angle and electrochemical polarization curve were used to detect the surface of the treated surface, and the structure, element composition and surface micro-morphology of the treated surface were measured by Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), laser confocal scanning microscope, contact angle and electrochemical polarization curve. and the wettability and the corrosion resistance are characterized. The results show that the perfluorooctanoic acid solution is a neutral solution with good diffusibility and wettability, can penetrate the porous rust layer to reach the surface of the base material, form the adsorption film, and destroy the binding action of the rust layer and the base material. In addition, the solution of the perfluorooctanoic acid solution at a concentration of 150g/ L was superior to the other concentration for the treatment with the rust surface. (2) Although the wettability and the permeability of the perfluorooctanoic acid solution are good, the corrosion resistance and the adhesion to the stainless steel surface are not significant, and the silane coupling agent has the advantages of no pollution, wide application, good film-forming effect, excellent adhesive property of the organic coating and the like, The method comprises the following steps of: mixing a perfluorooctanoic acid solution and a silane coupling agent (KH550, KH560) to generate a synergistic effect, carrying out dipping treatment on the stainless steel surface, heating the surface to form a film, performing performance detection on the prepared surface film to determine the optimal hydrolysis, Curing process parameters. The results show that the PFOA/ KH550 film and the surface of the PFOA/ KH560 film have a polymerization crosslinking reaction, and the PFOA/ KH550 film is stronger than the surface of the substrate; when the mass ratio of the KH550 to the PFOA is 1: 1, the solution concentration of the KH550 is 10%, and the curing time is 1. 5h, the surface film prepared when the curing temperature is 150 DEG C is the largest in thickness, the coating rate of the metal matrix is the largest, the sealing property of the film is the best, the wettability is moderate, and the corrosion resistance is obviously improved; whether under different hydrolysis processes or under different curing processes, The performance of the prepared PFOA/ KH550 film is superior to that of the PFOA/ KH560 film. (3) The final purpose of pre-treatment on the surface of the stainless steel was to match the coating, and the surface of three kinds of pre-treatment (the surface of the surface without treatment, the surface with the rust treated with KH550/ PFOA mixed solution) was studied in this paper. The matching effect of the rusted surface treated with KH560/ PFOA mixed solution and the epoxy organic coating. The results show that the mechanical properties of the surface coatings treated with the KH550/ PFOA solution are superior to those of the other two types. The surface coatings treated with the KH550/ PFOA solution only have the least damage to the surface coating treated by the KH550/ PFOA solution and only produce the micro-color change; after the coating sample is subjected to the drawing test, The adhesion between the surface treated by KH550/ PFOA solution and the epoxy organic coating is higher than that of the other two surfaces.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4
本文编号：2426017
[Abstract]:In recent years, people have been plagued by the problem of rust on the metal surface before painting. Because of the complexity and diversity of the rust component, it not only affects the adhesion of the coating, but also affects the corrosion resistance of the coating, so it is necessary to clean the surface rust layer. The traditional method of derusting can cause the problems of environmental pollution and cost, so the method of coating directly on the rust layer has become a hot spot. In the past, phosphoric acid and tannic acid are used to treat the rust layer, and the disadvantage is that it is not allowed to penetrate into the inside of the porous rust layer, and the amount of the acid is also difficult to control. In order to solve these problems, the paper chose the perfluorooctanoic acid solution (PFOA) with high surface activity, and carried out the work around it and the rust layer, and the contents and results were as follows: (1) The dipping treatment of the stainless steel surface was carried out by using the perfluorooctanoic acid solution. Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), laser confocal scanning microscope, contact angle and electrochemical polarization curve were used to detect the surface of the treated surface, and the structure, element composition and surface micro-morphology of the treated surface were measured by Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), laser confocal scanning microscope, contact angle and electrochemical polarization curve. and the wettability and the corrosion resistance are characterized. The results show that the perfluorooctanoic acid solution is a neutral solution with good diffusibility and wettability, can penetrate the porous rust layer to reach the surface of the base material, form the adsorption film, and destroy the binding action of the rust layer and the base material. In addition, the solution of the perfluorooctanoic acid solution at a concentration of 150g/ L was superior to the other concentration for the treatment with the rust surface. (2) Although the wettability and the permeability of the perfluorooctanoic acid solution are good, the corrosion resistance and the adhesion to the stainless steel surface are not significant, and the silane coupling agent has the advantages of no pollution, wide application, good film-forming effect, excellent adhesive property of the organic coating and the like, The method comprises the following steps of: mixing a perfluorooctanoic acid solution and a silane coupling agent (KH550, KH560) to generate a synergistic effect, carrying out dipping treatment on the stainless steel surface, heating the surface to form a film, performing performance detection on the prepared surface film to determine the optimal hydrolysis, Curing process parameters. The results show that the PFOA/ KH550 film and the surface of the PFOA/ KH560 film have a polymerization crosslinking reaction, and the PFOA/ KH550 film is stronger than the surface of the substrate; when the mass ratio of the KH550 to the PFOA is 1: 1, the solution concentration of the KH550 is 10%, and the curing time is 1. 5h, the surface film prepared when the curing temperature is 150 DEG C is the largest in thickness, the coating rate of the metal matrix is the largest, the sealing property of the film is the best, the wettability is moderate, and the corrosion resistance is obviously improved; whether under different hydrolysis processes or under different curing processes, The performance of the prepared PFOA/ KH550 film is superior to that of the PFOA/ KH560 film. (3) The final purpose of pre-treatment on the surface of the stainless steel was to match the coating, and the surface of three kinds of pre-treatment (the surface of the surface without treatment, the surface with the rust treated with KH550/ PFOA mixed solution) was studied in this paper. The matching effect of the rusted surface treated with KH560/ PFOA mixed solution and the epoxy organic coating. The results show that the mechanical properties of the surface coatings treated with the KH550/ PFOA solution are superior to those of the other two types. The surface coatings treated with the KH550/ PFOA solution only have the least damage to the surface coating treated by the KH550/ PFOA solution and only produce the micro-color change; after the coating sample is subjected to the drawing test, The adhesion between the surface treated by KH550/ PFOA solution and the epoxy organic coating is higher than that of the other two surfaces.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4
【参考文献】
相关期刊论文 前1条
1 肖进新,江洪;碳氟表面活性剂[J];日用化学工业;2001年05期
，本文编号：2426017
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