【摘要】 以对 -苯基苯酚为原料 ,通过醚化、酰化和氧化反应 ,合成了一系列 4′-正 -烷氧基联苯 - 4 -甲酸 .化合物的结构通过元素分析、红外光谱、核磁共振波谱等方法确证 .化合物 3的液晶行为用示差扫描量热法 (DSC)、偏光显微镜 (POM)表征 .发现化合物 3加热至各自的熔点以上都能形成液晶态 ,在液晶态可以观察到近晶相和向列相的典型织构 .随分子中末端烷氧基碳原子数增加 ,化合物 3的熔点 (Tm)和液晶态的清亮点(Ti)呈规律性变化 .近晶相范围和近晶相 -向列相转变温度渐增 ,而向列相温度范围递减 ,至十二烷基时 ,仅呈现近晶性 .更多还原

【Abstract】 A series of 4′-n-Alklxybiphenyl-4-Carboxylic acids are synthesized via etherification, acetylation and oxidation by using 4-phenylphenol as raw material. The compounds are identified by using elemental analysis, infrared spectra and nuclear magnetion resonance. The liquid crystalline behavior of the compound 3 is characterized by differential scanning calorimetery(DSC) and polarizing optical microscopy(POM). It is found that the compound 3 went into liquid crystal phase when heated to their T m. The typical smectic phase and nematic phase texture can be observed. Both melting point(T m) and isotropization temperature(T i) of compound 3 change regularly with the carbon numbers of the end alkoxy groups. There is a gradual increase in smectic phase length and so do the smectic-nematic transition temperature. At the same time there is a gradual decrease in nematic phase length until in the dodecyl, purely smectic properties are encountered.更多还原