含水不饱和聚酯的动态流变行为和微观结构

使用三乙醇胺(TEA)和Span80复合乳化剂制备含水不饱和聚酯树脂,改变水/乳化剂的比率(W/E)和TEA∶Span80复合比例,通过动态流变法研究含水不饱和聚酯树脂乳液的流变性质,结合光学显微镜和SEM扫描电镜分析微观结构,并测试固化树脂材料的力学性能。实验表明在一定含水量和乳化剂复合比例下,可以制备出乳胶粒子界面膜强度高,粒子数密度高,分布均匀,且乳液稳定性好的含水不饱和聚酯(WCUP)树脂,得到力学强度高的固化树脂,并得到了复合乳液黏度随应力和频率的流变规律。最佳配比TEA∶Span80=9.0∶1.0,W/E=19.2时,其树脂固化体系的拉伸强度和冲击强度比单使用TEA体系分别提高了34%和67%。

Dynamic rheology and microstructures of water-containing unsaturated polyester

The dynamic rheological behavior of the water-containing unsaturated polyester(WCUP) emulsion was discussed in this paper.Triethanol amine(TEA) or its composite with Span80 was used as emulsifier.The microstructures of emulsions were studied through changing the ratio of water to the emulsifiers by optical microscopy,scan election microscopy.The cured resins were obtained by adding curing agent.The relationships between the complex viscosity of the prepared emulsion vs shear stress(τ) or frequency(ω) were achieved by dynamic rheological analysis.It was found that at certain ratio of water to emulsifiers of TEA/Span80,the interfacial strength of emulsion and number density of the emulsion particle were higher,its distribution was more uniform and the emulsion were of high stability,and the cured resin had high mechanical strength meanwhile the relationship of the emulsion viscosity with its shearing stress was observed.At the optimum ratios of TEA to Span 80,which W/E was 19.2 and TEA∶Span 80 was 9.0∶1.0,the tensile strength and impact strength of the cured resin were increased 34% and 67% respectively compared to that of WCUP using only TEA as emulsifier.