软段结构对聚氨酯-聚丙烯酸酯复合乳液乳胶粒形态结构的影响

Effect of the soft segments construction on morphology of aqueous polyurethane/polyacrylate latexes

为了探讨聚氨酯水分散液(WPU)的软段结构对聚氨酯-聚丙烯酸酯复合乳液(PUA)乳胶粒子形貌结构的影响,首先分别合成了不同软段结构的WPU,然后以其为种子乳液并滴加溶有引发剂的丙烯酸酯混合单体形成预乳液,升温聚合后得到PUA。通过对乳胶粒径测试和形貌观察发现,软段分子量较小时,形成的PUA乳胶粒没有明显的核/壳结构,软段分子量较大时,形成过渡层型、梯度型和草莓型结构的核/壳结构PUA乳胶粒,采用两种分子量的软段共混得到的PUA乳胶粒具有复杂的核/壳结构。

In order to research the effect of the soft segments construction of the aqueous polyurethane（WPU） dispersion on latexes morphology of the aqueous polyurethane/polyacrylate composite emulsions（PUA）,the PUA was prepared by emulsion polymerization used WPU as seed emulsion mixed acrylic monomers and initiators previously.The particle size distribution and morphology of the PUA latexes were investigated respectively.The results showed that the PUA latexes do not appear obviously core-shell structural feature as the WPU with shorter soft segment chain,while they form a mixture structure of the transition,gradient and strawberries types as it with increased soft segments chain length.The PUA latexes present more complex core-shell structural feature as the WPU with the mixtures soft segments of shorter and longer chain.