【摘要】 为了提高丙烯酸树脂类钝化膜的耐蚀性能,以三甲基氯硅烷对纳米SiO2进行表面改性,制成分散液后与硅烷偶联剂KH-563、丙烯酸树脂及无机盐Ni(CH3COO)2等复配成无铬钝化液,对热镀锌板进行复合钝化。采用红外光谱测试了改性纳米SiO2的结构,采用粒度仪分析其粒径;利用扫描电镜和能谱分析了复合钝化膜的微观形貌和成分;采用电化学及中性盐雾试验分析了复合钝化膜的耐蚀性能。结果表明:纳米SiO2改性后,表面能降低,分散性良好;改性纳米SiO2与丙烯酸树脂发生交联作用,形成了网状结构,提高了复合钝化膜的致密性;复合钝化耐蚀性能较丙烯酸树脂钝化膜及热镀锌板显著提高。更多还原

【Abstract】 The surface of nano- SiO2was modified by trimethyl chlorosilane.Resultant modified nano-SiO2was then prepared into dispersion and mixed with silane coupling agent KH-563,acrylate resin and nickel acetate [Ni( CH3COO)2] to afford Cr-free passivation fluid. The passivation fluid was adopted to passivate hot galvanized steel sheet so as to improve the corrosion resistance. The chemical structure of nano-SiO2modified by trimethyl chlorosilane was analyzed with an infrared spectrometer,and its grain size was determined with a grit size analyzer. The morphology and composition of as- prepared composite passivation film were analyzed with a scanning electron microscope and an energy dispersive spectrometer,and its corrosion resistance was evaluated by electrochemical tests and neutral salt-spray test. Results showed that modified nano-SiO2had reduced surface energy and good dispersion,and it was able to form network-like structure by participating in cross-linking with acrylate resin thereby increa-sing the compactness of the composite passivation film. As a result,as-prepared composite passivation film possessed much better corrosion resistance than acrylate resin passivation film and hot galvanized steel sheet substrate as well.更多还原