端基含双键的液晶单体的合成

Synthesis of Liquid Crystalline Monomers with End Groups Containing Double Bonds

以对羟基苯甲酸甲酯为起始原料,通过醚化和酯化反应合成了系列端基为双键的液晶化合物(dnm),其结构经~1H NMR,^(13)C NMR,FT-IR和元素分析表征。并采用差热扫描量热仪(DSC)和热台偏光显微镜(POM)研究了其液晶性能。结果表明:目标化合物均为互变性热致向列相液晶单体,且其熔点和液晶相转变温度随烷基碳数(m)增加先增大后减小。

A series of liquid crystal monomers（ d nm ） with end groups containing double bonds were synthesized by esterification and etherification reaction with methyl 4-hydroxybenzoate as the starting material. The structures were characterized by 1 H NMR, 13 C NMR, FT-IR and elemental analysis. The liquid crystal properties were measured by differential scanning calorimetry（DSC） and thermal polarizing microscope（POM）. It was found that all the target products exhibited enantiotropic nematic mesophase. The melting point and the phase transition temperature of the monomers increase first and then decrease with increasing of carbon number.