含短氟碳链结构水性环氧树脂的制备及性能

Preparation and properties of waterborne epoxy resin with short fluorocarbon chain structure

采用环氧树脂(E-44)、异佛尔酮二异氰酸酯(IPDI)、1,1,1,3,3,3-六氟-2-丙醇(HFIP)、二乙烯三胺(DETA)为主要原料,合成了一种含短氟碳链结构的水性环氧乳化型固化剂,并与氟改性环氧树脂乳化配制成一种环保、疏水型含短氟碳链结构的水性环氧树脂。采用接触角测定仪、FTIR、AFM、TGA和DMA对该树脂的结构、固化膜的表面性能、热性能及力学性能进行表征和考察。结果表明:与无氟体系相比,含氟结构改性的环氧体系的耐热性和疏水性得到一定程度的提高,较低的氟含量2.4%(氟元素在环氧固化物中的质量分数,下同)即可达到疏水的效果。随着氟含量增加到5.1%,环氧树脂固化膜的铅笔硬度从3H提高到5H,但是附着力降低了1级,玻璃化转变温度从68℃提高到了80℃,同时表面粗糙程度也得到提高,使得水接触角进一步增大到最佳的98°,得到的固化膜具有最佳的热稳定性,其最大热分解温度为373.1℃。

A waterborne self-emulsification epoxy curing agent modified with short fluorocarbon chain was synthesized using epoxy resin(E-44), isophorone diisocyanate(IPDI), 1,1,3,3,3-hexafluoro-2-propanol(HFIP) and diethylenetriamine(DETA) as main raw materials. Then, it was emulsified with fluorinemodified epoxy resin to prepare an environment-friendly hydrophobic waterborne epoxy resin. The structure of the resin, surface properties, thermal properties and mechanical properties of the cured films were characterized by contact angle tester, FTIR, AFM, TGA and DMA. The results showed that the heat resistance and hydrophobicity of the fluorine-containing epoxy system were higher than those of fluorine-free epoxy system to some extent, and lower fluorine content(2.4%, mass fraction of fluorine in epoxy cured substance, the same below) could make the cured film exhibit good hydrophobicity. With the increase of fluorine content to 5.1%, the pencil hardness of epoxy resin cured film increased from 3 H to 5 H, but the adhesion decreased by 1 level, and the glass transition temperature increased from 68 ℃ to 80 ℃. At the same time, the surface roughness was also improved, which further increased the water contact angle to an optimum value(98°). The cured film had the best thermal stability with a maximum thermal decomposition temperature of 373.1 ℃.