无皂乳液聚合制备PUA乳液的稳定性研究

采用无皂乳液聚合法制备丙烯酸酯一聚氨酯复合乳液（PUA）。HEMA作为交联剂引入到聚氨酯主链上，利用核壳交联制得复合乳液。研究了不同的合成工艺、丙烯酸酯单体、DMPA及HEMA含量，引发剂种类等对乳液稳定性的影响。研究发现，将丙烯酸酯单体溶胀于水性聚氨酯乳液中再进行聚合可大大提高乳液的稳定性；采用1．0％～12％的AIBN为引发剂、DMPA质量分数为4．5％、HEMA质量分数为4．0％～4．5％、丙烯酸酯单体质量分数为30％时，可制得外观及稳定性良好的PUA复合乳液。

Study on stability of polyurethane-polyacrylate hybrid emulsion prepared by soap-free emulsion polymerization

Polyurethane-polyacrylate hybrid emulsion was prepared by soap-free emulsion polymerization in this paper. With the shell ofpolyurethane（PU） and the core ofpolyacrylate（PA）, the core-shell structure of latex particles was synthesized with 2-hydroxyethyl methacrylate（HEMA） as the corsslinking monomer.Factors influencing the stability of emulsion were discussed in details, including the synthesis process, the kinds of initiators and the contents of acrylic monomers, dimethylol propionic acid（DMPA） and 2-hydroxyethyl methacrylate. The hybrid emulsion with good appearance and excellent stability was prepared by polymerization after acrylic monomers swollen in polyurethane emulsion and using 1.0 to 1.2% by weight of AIBN, 4.0% to 4.5% by weight of HMEA, 30% by weight of arylic monomers and 4.5% by weight of DMPA.