【作者】 高翔；

【导师】 何德良；

【作者基本信息】 湖南大学 ， 应用化学， 2011， 硕士

【摘要】 带锈涂料可直接涂刷于存在一定残余锈蚀的钢铁表面,简化了传统涂料涂装前的表面处理程序,大大降低了涂装成本和对环境及施工人员的危害,其防锈性能也优于常规的防腐蚀涂料,目前低表面处理带锈涂料及其配套中涂漆已成为重防腐涂料研究的热点和重点。本文在综述了热镀锌碳钢材料大气腐蚀现状和低表面处理带锈涂料研究进展的基础上,制备了热镀锌钢构用有机转锈剂,并使用上述有机转锈剂制备了集稳定,转化、渗透为一体的多功能低表面处理带锈富锌涂料。针对现有的传统中涂漆不能和带锈涂料形成优异的配套性能的现状,制备了带锈富锌涂料专用的铝锆偶联剂改性环氧铝粉中涂漆。本论文的主要研究工作如下:1、热镀锌钢构用有机转锈液的制备与性能研究。利用扫描电镜（SEM）和能量散射谱（EDS）研究了热镀锌碳钢材料的镀层组织形貌和物象组成成分。采用湿热交替加速腐蚀试验模拟了热镀锌钢材在含有氯化物的大气环境中的腐蚀,采用X射线衍射谱（XRD）分析了腐蚀产物的主要有构成。依据上述研究结果采用正交实验法制备了具有一定磷化、钝化和除油功能的有机转锈剂。采用相关国家标准和方法研究了转锈液的基本物理性能、转锈液处理后金属的防锈性能以及锈转化效率。结果表明有机转锈剂在锈蚀热镀锌表面形成防锈膜层,膜层附着力≦2级,耐CuSO₄点滴162 S,3%NaCl溶液浸渍17 h,防锈期50 d,转锈剂的转化效率为0.124 Kg·m^-2。2、低表面处理带锈富锌涂料的制备及性能研究。采用环氧树脂E-44作为主要的成膜物质,并掺杂聚乙烯醇缩丁醛树脂、氨基树脂、环氧改性有机硅树脂作为辅助成膜物质;采用锌粉和多种化学防锈颜料组合应用以增强涂料的电化学和化学防锈性能;以第2章制备的有机转锈剂作为转锈组分来制备低表面处理带锈富锌涂料。采用正交实验法考察了成膜物质、电化学防锈颜料锌粉、主化学防锈颜料、有机转锈剂对对涂层的物理机械性能、化学防锈性能、带锈涂装性能以及施涂性能等的影响。制备的低表面处理带锈富锌涂料具有优良的物理机械性能和防锈性能,其硬度达到4 H,耐盐水浸泡60 d不返锈,耐盐雾﹥800 h,施涂性能良好。同时采用盐雾试验考察了转锈剂对带锈涂料在无锈基体上耐蚀性能的影响,当其用量的质量份为6时涂层具有最好的耐腐蚀性能。3、铝锆有机金属偶联剂改性环氧铝粉涂料的制备及性能研究。采用铝锆偶联剂对鳞片状铝粉进行表面改性,将改性后的铝粉用作防锈颜料制备了一种环氧铝粉涂料。EDS和SEM照片显示改性后的铝粉分散性能得到改善,表面斑点状缺陷得到修复,涂层更加平整、致密,物理屏蔽性能提高。研究同时表明经2.5%偶联剂改性的环氧铝粉涂料具有良好的物理机械性能,硬度达到4 H,耐3%盐水浸泡65 d无锈蚀,不起泡。涂层体系在3.5%NaCl溶液中的的电化学阻抗谱（EIS）测试表明,浸泡52 d后未改性的涂层基本上失去了对基体的保护作用,改性涂层的阻抗值仍可达到10⁶Ω·cm²,涂层对基体仍具有一定的保护作用,且当偶联剂的用量为2.5%时环氧铝粉涂层具有最好的防护性能。Tafel曲线测试表明铝锆偶联剂改性后涂层的自腐蚀电流减小,腐蚀速率下降。涂层体系的配套性能测试表明底漆和中涂漆具有良好的相容性,防腐性能,底漆和中涂漆在冷热收缩性、伸张强度等力学变化方面具有较强的适应性。更多还原

【Abstract】 The surface tolerant residual rust coatings can be painted onto the surface rusted directly,which can avoid the treatment before painting, save large amounts of expenditure and reduce the harm for the environment, constructers and have better properties than traditional coatings. In recent years the residual rust coatings have became hotspots and focuses in the studies of heavy-duty coatings. The atmospheric corrosion of hot-dip galvanized steel and development of residual rust coatings are reviewed in details. In this thesis, an organic rust conversion solution was prepared, and with the rust converter we have got the surface tolerant residual rust zinc-rich coating incorporating stabilization, transform, permeate into an organic whole. On the basis of conventional intermediate coating can’t cooperate well with residual rust primer, the Al-rich epoxy coatings modified with aluminium zirconium coupling agent was prepared. The main points of this dissertation are summarized as follows:1、Preparation and investigation of organic rust converter for hot-dip galvanized steel. Morphology and composition of the hot-dip galvanized steel was studied using the scanning electron microscopy （SEM） and energy dispersive x-ray （EDS） . To investigate zinc atmospheric corrosion in the presence of chloride alternate wet and heat test has been employed, the texture of the corrosion products were evaluated employing X-ray diffraction. According to the experimental results, an organic rust conversion solution which had several functions such as phosphorization, passivation, oil removal was prepared. The physical properties, and corrosion protection of hot-dip galvanized steel were studied. The results exhibited the organic rust converter could formed a compact and uniform film, the film adhesive force did not exceed 2 grade, the film could resist cupric sulfate spot test for 162 S and dipping test in the 3%NaCl solution for 17 h. Besides, the antirust time could be up to 50 days,conversion efficiency reached 0.124 Kg·m^-2.2、Preparation and evaluation of surface tolerant residual rust zinc-rich coating. During the preparation, the epoxy resin E-44 was selected as the main film former and polyvinyl butyral resin, amino resin, epoxy-silicone resin as the auxiliary materials. The flake zinc powder and multiple antirust pigments were used to improve corrosion resistance of the coatings. The organic rust conversion solution prepared in chapter 2 was used as one component of coating. The physical mechanical properties, anticorrosive properties, application over rust and construction performance of the coating were optimized by orthogonal experiments. The coating showed good physical mechanical properties, the pencil hardness reached 4 H. After immersing in 3%NaCl solution for 60 days or salt spray test for 800 h the coating had no blister and rust spot. The effect of rust converter on the corrosion resistance of residual rust coatings application over metal without rust was investigated by salt spray test. The results indicated coatings exhibited the highest protective performance while 6 qualities ratio rust converter was used.3、Preparation and performance study of Al-rich epoxy coatings modified with aluminium zirconium organic metal coupling agent. The surface of Al flake powder was modified by aluminium zirconium coupling agent. The resulting flakes were incorporated into epoxy coatings as anticorrosive pigments. The EDS and SEM tests indicated that the coupling agent improved the dispersion of Al flake powder, and the spot-like surface defects were repaired, so the flatness, adherent and shielding effect of coatings was greatly enhanced. Meanwhile, the coatings modified with 2.5wt% aluminium zirconium coupling agent displayed good physical mechanical properties, the pencil hardness reached 4 H. After exposure of simples in 3% NaCl solution for 65 days, no blister and rust spot was found on the surface. The electrochemical impedance spectroscopy （EIS） results of coatings in 3.5% NaCl solution showed that after 52 days immersion the coatings before modification had no corrosion resistance, the coatings after modification still displayed good corrosion protection with impedance value of 10⁶Ω·cm² and the epoxy coatings exhibited the highest protective performance while 2.5wt% coupling agent was used. Tafel test indicated the coatings displayed smaller corrosion rate after modification. The test of supporting system showed the intermediate coating cooperated well with primer, composite coating system exhibited good corrosion performance, cold and hot fatigue property, retractility.更多还原