交联型有机硅改性聚氨酯丙烯酸酯乳液的合成及其性能

为开发出一种机械性能优良、耐水性较佳的聚氨酯，以聚醚多元醇、甲苯二异氰酸酯、二羟甲基丁酸、甲基丙烯酸羟乙酯合成双键封端的水性聚氨酯，再与丙烯酸单体、乙烯基三异丙氧基硅烷(A173)、端乙烯基聚二甲基硅氧烷（Vi-PDMS）进行乳液聚合，得到交联型有机硅改性聚氨酯丙烯酸酯乳液。采用红外光谱、吸水率、机械性能测试等进行表征。结果表明，以A173或Vi-PDMS对PUA进行改性，胶膜机械强度及吸水性能均得到明显改善；A173可显著提高机械强度，但其断裂伸长率下降剧烈，耐水性能提高有限；Vi-PDMS可显著提高耐水性，但过量会降低其机械性能。采用2.5% A173和 3% Vi-PDMS复合改性，胶膜断裂强度和断裂伸长率可达1.65MPa?s、 242%，吸水率降至8.32 %。

Synthesis and properties of crosslinked polyurethane acrylate modified with organic silicon

For developing water-based polyurethane with excellent mechnical properties and better water resistance, a prepolymer with vinyl end-capping was prepared using polyether polyols, toluene diisocynate, 2,2-dimethylolbutanoic acid and 2-hydroethyl methacrylate. These emulsions were used to copolymerize with methyl methacrylate, butyl acrylate and silicon monomers, including vinyltriisopropoxysilane (A173) and vinyl-ended polydimethylsiloxane (Vi-PDMS), to synthesize the silicon modified polyurethane acrylate emulsion. The chemical structure of the Si-PUA emulsion was characterized by Fourier Transform Infrared Spectrum. The water absorption and mechanical property of the Si-PUA film were investigated. The result showed that the increasing dose of A173 in the copolymerization could enhance the strength but reduce the elongation at break of the Si-PUA films. The presence of Vi-PDMS in the synthesis could give rise to better water resistance of the films but result in lower mechanical properties, especially for higher content of Vi-PDMS. When using 2.5% A173 and 3% Vi-PDMS in the synthesis of Si-PUA, the breaking strength of the resultant film was up to 1.65MPa, the elongation at break was 242%, and water absorption was as low as 8.32 %.