New amphiphilic polycarbonates with side functionalized cholesteryl groups as biomesogenic units: synthesis, structure and liquid crystal behavior
作者:Xiaoxu Xu、Xiaofeng Liu、Qun Li、Jianshe Hu、Qifan Chen、Liqun Yang、Yanhua Lu
DOI:10.1039/c7ra00360a
日期:——
functionalized-cholesterol based aliphatic polycarbonates is described through the ring-opening polymerization and coupling reaction. The chemical structures, liquid crystal (LC) behavior, and thermal stability of the chiral monomers and copolymers obtained in this study were characterized using Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magneticresonance (1H NMR) spectroscopy, gel
diffraction measurements. The experimental results demonstrated that the mesogenic arm structures strongly affected the phase behavior. 4a did not show any liquidcrystallinity, while 4b, 4c and 4d revealed reversible cholesteric phase transition. As the intermedius alkyl chain of the star-shaped compounds lengthened (from n = 2 to n = 8), their melting points decreased but mesomorphic temperature ranges
摘要 以1,3,5-三羟基苯单元为核心,ω-胆甾醇烷基二酸单酯为介晶臂,设计合成了一类新的星形胆甾型液晶。它们的化学结构已通过元素分析、FT-IR 和 1H NMR 确认。通过差示扫描量热法、热重分析、偏光显微镜和 X 射线衍射测量研究了介晶性质和热稳定性。实验结果表明介晶臂结构强烈影响相行为。图 4a 没有显示任何液晶性,而 4b、4c 和 4d 显示可逆胆甾相转变。随着星形化合物的中间烷基链加长(从 n = 2 到 n = 8),它们的熔点降低,但介晶温度范围增加。焦点圆锥纹理,在液晶状态下可以观察到胆甾相之一。