Abstract: A series of waterborne polyurethane modified with epoxy resin, which was mixed into prepolymer before emulsification, were prepared. The structure and morpological change of waterborne polyurethane/epoxy resin (WPU/EP) emulsion during storage was characterized by Fourier transform infrare spectroscopy(FT-IR) and transmission electronic microscope(TEM). The results indicated that the reason of demulsification was mainly related to the reaction between carboxyl and epoxy groups.

Key words: waterborne polyurethane, epoxy resin, stability of emulsion

摘要： 以乳化前掺混环氧树脂的方式制备了一系列环氧树脂改性聚氨酯水乳液，通过红外光谱（FT-IR）、透射电镜（TEM）等手段表征了乳液在贮存过程中的化学结构及乳胶粒子形态的变化，发现乳液在存放期间容易破乳的主要原因是由于水乳液聚氨酯分子侧链上亲水基团羧基与环氧树脂中环氧基团发生缓慢的化学反应造成的。

关键词: 水性聚氨酯, 环氧树脂, 乳液稳定性