硅氧烷低聚物改性水性环氧树脂及其性能研究

Synthesis and Characterization of Siloxane Oligomer Modified Waterborne Epoxy

用甲基丙烯酸改性环氧E-44合成水性环氧树脂,再以物理共混方式用自制硅氧烷低聚物改性水性环氧树脂。采用红外光谱对树脂结构进行表征;用改性树脂制备固化涂层,考察了涂层固化后的基本性能;并利用热重分析和差示扫描量热法分析了固化膜的热稳定性和玻璃化转变温度。结果表明:硅氧烷低聚物对改性水性环氧树脂的附着力、吸水率、耐化学介质性能影响不大;加入硅氧烷低聚物后涂膜的铅笔硬度从3H提升至4H;随着硅氧烷低聚物含量的增加,达到最大热失质量速率时的温度从364.5℃提升至433.0℃,涂膜的热稳定性提高。

A waterborne epoxy resin was prepared by E- 44 epoxy modified with methacrylic acid, which was further modified with self-made siloxane oligomers via physical blending process. The structure of epoxy resin was characterized by FT-IR. The properties of the cured film derived from the coatings based on the modified epoxy resin were investigated. The glass transition temperature and the thermal decomposition temperature of the cured film were also investigated by DSC and TGA respectively. The results showed that siloxane oligomers had little effect on the adhesion, water absorption, and chemical resistance of the modified epoxy, and enable the pencil hardness to increase from 3H to 4H. In addition, the increase of siloxane oligomer content might result in the improved thermal stability, showing higher temperature at maximum mass loss rate increased from 354. 5℃ to 433℃.