水性聚氨酯-丙烯酸酯复合乳液的合成与表征

为开发高性能且环保的丙烯酸酯改性水性聚氨酯乳液，以甲苯二异氰酸酯、聚醚二元醇、二羟甲基丙酸（DMPA）和甲基丙烯酸甲酯为主要原料，采用原位乳液聚合法，先制得水性聚氨酯预聚物／乙烯基单体混合物，然后加入引发剂，经自由基乳液聚合得到聚氨酯一丙烯酸酯（PUA）复合乳液，并对影响复合乳液性能的因素进行了探讨．研究发现，PUA复合乳液的性能及外观与-NCO／-OH比（物质的量比，下同）、二羟甲基丙酸（DMPA）含量以及中和度等密切相关．当n（-NCO）：n（-OH）=1．3～1．4，-COOH质量分数在2．6％左右．中和度为90％～100％时，所得PUA复合乳液的外观好、性能佳．

Synthesis and Characterization of Water-Borne Polyurethane-Acrylate Hybrid Emulsion

In order to obtain a water-borne polyurethane emulsion modified by acrylic ester and possessing excellent performance and environmental advantages, toluene diisocyanate, polyether binary alcohol, dimethylol propionic acid (DMPA) and methacrylate were used as the main materials to prepare the water-borne polyurethane/vinyl monomer prepolymer by means of emulsion polymerization in situ. Then, by adding the initiator to the mixture, polyurethane-acrylate (PUA) hybrid emulsion was synthesized through free-radical emulsion polymerization. Moreover, the factors to affect the performance of the hybrid emulsion were investigated. The results indicate that the properties and appearance of the PUA hybrid emulsion are greatly relative to the -NCO/-OH ratio (mole ratio, below the same), the content of DMPA and the neutralization degree. When the-NCO/OH ratio, the mass fraction of -COOH and the neutralization degree are respectively controlled at 1.3 ～1.4, about 2.6% and 90% ～ 100%, the prepared emulsion is of good appearance and excellent performance.