梯度化环氧涂层的制备与结构研究

目的提高环氧涂层的耐候性能,简化多层涂层体系的施工工艺。方法以氨基官能团硅树脂和聚酰胺为固化剂,共同固化环氧树脂,利用硅树脂中聚硅氧烷链段的表面迁移特性,制备得到一种聚硅氧烷/环氧梯度化层,探讨制备过程中硅树脂的用量和所用溶剂对涂层组成和结构的影响规律,采用扫描电镜-X射线能谱(SEM-EDS)、红外光谱(FTIR)、水接触角等方法对涂层结构进行表征。结果选用氨基官能团硅树脂与聚酰胺质量配比为2:8、二甲苯和正丁醇质量配比为1:1作为溶剂,得到的复合涂层表面富集聚硅氧烷链,同时底面含大量聚酰胺链段,具有链段分布的梯度化的结构。该梯度化清漆涂层经960 h盐雾老化后,无起泡、开裂、锈蚀等现象发生,具有优良防腐性能;经960 h人工加速紫外老化,失光率与色差仅为1%和8.9%,耐候性能优于常规环氧涂层。结论通过氨基官能团硅树脂和聚酰胺共固化,使环氧涂层表面富集聚硅氧烷链段,形成梯度化结构,具有耐候、防腐一体化的功能。

Preparation and Construction of Graded Epoxy Coating

The paper aims toimprove the weatherability of epoxy coatings and simplify the construction process of multilayer coating systems. Amino-functional silicone resin and polyamide were used as curing agents to jointly cure epoxy resin. Based on the surface migration characteristics of polysiloxane segments in silicone resin, a polysiloxane / epoxy graded materials coating was prepared. The effects of the amount of silicone resin and the solvent on the coating composition and structure were discussed. Scanning electron microscope-X-ray energy spectroscopy (SEM-EDS), infrared spectroscopy (FTIR), and water contact angle were used to characterize the coating structure. When the mass ratio of amino-functional silicone resin to polyamide was 2:8 and the ratio of solvent was txylene:butanol=1:1, the surface of the obtained coating was rich in polysiloxane and the bottom was rich in polyamide chain of graded structure. The graded coating had no blistering, no cracking, no rust after 960h salt spray aging, showing excellent corrosion resistance. And after 960h accelerated UV aging, the light loss rate and the color difference of coating was only 1% and 8.9%, showing that its weatherability was better than that of conventional epoxy coatings. By using amino-functional silicone resin and polyamide to jointly cure epoxy resin, the surface of epoxy coating is rich in polysiloxane segments. The coating forms a graded structure with functions of weatherability and anticorrosion integration.