有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液的制备

将磺酸型聚酯多元醇、异佛尔酮二异氰酸酯（IPDI)和三羟甲基丙烷(TMP)在无有机溶剂参与的情况下进行预缩聚，以硅烷偶联剂γ-氨丙基三乙氧基硅烷（KH550）作为改性剂，加入双官能团单体甲基丙烯酸-β-羟乙酯(HEMA)，得到含乙烯基和有机硅封端的聚氨酯作为种子乳液，然后与甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)混合单体共聚，合成了有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液。 红外光谱的表征确定了有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液的化学结构；透射电子显微镜观察证实了此复合乳液具有明显的核壳结构；热重分析表明，经有机硅和丙烯酸酯改性后，胶膜的最大热失重温度提高了20 ℃，X射线衍射分析表明胶膜的结晶度降低，有利于提高膜的韧性。 力学性能测试及吸水率测试结果表明，当有机硅含量为1.9%时，胶膜的拉伸强度最高达到25.03 MPa，断裂伸长率为328%，此时膜的吸水率最低。

Preparation of Silicone Modified Sulfonated Polyurethane/acrylic Composite Emulsion

A prepolymer was prepared by reacting the obtained sulfonated polyester polyol with isophorone diisocyanate(IPDI) and trimethylolpropane(TMP). The seed emulsion containing viny and silicone was prepared by end-capping with bifunctional monomer β-hydroxyethyl methacrylate(HEMA) and modification by silane coupling agent γ-aminopropyl triethoxysilane（KH550). The silicone modified sulfonated polyurethane/acrylic composite emulsion was obtained by mixing methyl methacrylate(MMA) and butyl acrylate(BA) monomers. The silicone modified sulfonated polyurethane/acrylic composite emulsion was characterized by infrared spectroscopy. The core-shell structure of the composite emulsion was confirmed by the transmission electron microscopy. Thermogravimetric analysis showed that an increase of 20 ℃ of the largest thermal mass loss temperature could be observed for the organic silicon and acrylic modified films. Meanwhile, the crystallinity was decreased as revealed by X-ray diffraction result, which could help to improve the toughness of the film. In addition, when the organic silicon content is 1.9%, the tensile strength of the film is up to 25.03 MPa, its elongation at break is 328%, and has the lowest water absorption.