季铵盐型水性环氧树脂乳化剂的制备及特性研究

Synthesis and properties of quaternary ammonium water-borne epoxy resin surfactants

以二乙醇胺、环氧E-44树脂等为原料,合成叔胺结构中间体,与溴乙烷反应制得季铵盐型水性环氧树脂乳化剂,以相反转技术乳化环氧树脂E-44。研究了乳化剂合成过程中反应温度、反应时间和环氧基转化率的关系;探讨了乳化剂用量对水性环氧树脂水分散性,稳定性及固化性能的影响。利用红外光谱对产物的结构进行了表征。结果表明:二乙醇胺与环氧E-44树脂在80℃反应3 h,环氧基转化率可达98%以上;乳化剂用量为ω=22%时其乳化效果及所制得乳液的稳定性最好。DSC和TG分析结果表明,水性环氧树脂乳液和工业环氧树脂E-44比较,固化后热性能基本一样,分解温度约在350℃,但其玻璃化转变温度有所降低,说明其韧性有一定提高。

A kind of tertiary amine intermediate was prepared by the reaction of E-44 epoxy resin with diethanolamine,followed by reaction with bromoethane to give quaternary ammonium salt wa- ter-borne epoxy resin surfactants. The waterborne E-44 epoxy resin was prepared by the phase inversion technique. The relationship between the conversion rate of epoxy group and the reaction time and temperature was studied. The effect of concentration of the emulsifier on water dispersibility, stability and curing properties of the waterborne epoxy emulsion was also investigated. The structure of the polymer was characterized by FT-IR spectroscopy. The results showed that upon the reaction of diethanolamine with epoxy resin E-44 at 80℃ the conversion rate of epoxy group could reach over 98% after the reaction had taken place for 3 h. The emulsifying performance and emulsion stability were the best when the amount of the emulsifier used was 22 %. The DSC and TG analyses had shown that the thermal property of the waterborne epoxy emulsion and the epoxy resin E-44 after curing was similar, and decomposition occurred at about 350℃. The glass transition temperature of the waterborne epoxy emulsion was lower than that of epoxy resin E-44, as evidenced by its enhanced toughness.