光响应微交联液晶聚氨酯的合成及性能

Synthesis and Properties of Light-Responsive Micro-crosslinked Liquid Crystal Polyurethane

采用正丁基苯胺和对羟基联苯为原料,并通过引入甲基丙烯酸异氰基乙酯合成两种带有活性官能团的液晶大单体2-[4-正丁基-4′-(11-羟基烷氧基)偶氮苯]氨酯基甲基丙烯酸乙酯(M11)和4,4′二[6-(丙烯酰氧基)6-羟基己氧基]联苯(BMBP)。然后,以M11为基体,BMBP为交联剂制备了两种不同交联度的液晶聚氨酯(LCPU),并通过溶液涂覆方式将其涂覆在具有预制沟槽的低密度聚乙烯薄膜上制备光致变形薄膜。通过核磁共振波谱仪、差示扫描量热分析仪、偏光显微镜和激光位移传感器等对材料的结构、形貌和性能进行了表征。结果显示液晶大单体和LCPU均具有较好的液晶性。其中微交联液晶聚氨酯(MCLCPs)具有较好的热稳定性和拉伸性能,断裂强度和断裂伸长率增大,分别达到32 MPa和1183%。光响应性能测试结果表明,复合薄膜具有较快的光响应速度和较好的循环稳定性,经MCLCPs涂覆的薄膜具有较好的光致变形能力,最大偏转角为90°,达到最大偏转角所需时间为7 s。

Using n-butyl aniline and p-hydroxybiphenyl as raw materials,two kinds of liquid crystal monomers with active functional groups were synthesized by introducing isocyanyl ethyl methacrylate 2-[4-n-butyl-4′-(11-hydroxylalkoxy)azobenzene]aminoester ethyl methacrylate(M11)and 4,4′bis[6-(acrylloxy)6-hydroxy-hexoxy]biphenyl(BMBP).Then,two kinds of liquid crystal polyurethanes(LCPU)with different crosslinking degrees were prepared using M11 as matrix and BMBP as crosslinking agent,and the photodeformed film was prepared by solution coating on low density polyethylene film with prefabricated grooves.The structure,morphology and properties of the materials were characterized by nuclear magnetic resonance spectroscopy,differential scanning calorimetry,polarizing microscope and laser displacement.The results show that the large liquid crystal monomer and LCPU all have good liquid crystal properties.The micro-crosslinked liquid crystal polyurethane(MCLCPs)has good thermal stability and tensile properties,the breaking strength reaching 34 MPa and elongation at break reaching 34 MPa and 1183%.The experimental results show that the composite film has a fast light response speed and good cycling stability.The film which coated by MCLCPs has the best photoinduced deformation ability,and the maximum deflection angle is 90°in 7 s.