【作者】 周光强；

【导师】 高建峰；

【作者基本信息】 中北大学 ， 高分子化学与物理， 2012， 硕士

【摘要】 含偶氮苯基的侧链液晶高分子作为功能材料在液晶显示、记录存储介质和光电转换等诸多领域具有很大的应用前景。设计合成新型的液晶化合物，了解结构与液晶性能之间的关系仍然是当前研究的重要内容。本文根据王新久和Warner（W-W）理论设计了含偶氮苯基的聚硅氧烷液晶模型，通过改变基元结构中的柔性部分、刚性部分及端基部分制得了一系列含不同侧链的偶氮液晶高分子：产物1～6，其中产物2比产物1多出一段柔性部分-CH2CH2CH2O-；产物3比产物2多出一个刚性苯环Ar；产物4，产物5和产物6含有不同的末端尾基，分别为：SO3H、NO2、COOH，上述六种化合物在分子设计上有递进关系，以便研究液晶分子结构变化对液晶性能的影响。该系列化合物结构经红外（FT-IR）表征均正确；然后在偏光显微镜（POM）下获取其织构信息，表明六种化合物均为近晶型液晶，但织构各异；再经差示扫描量热仪（DSC）测试得出其相变区间（熔点Tm～清亮点Ti），产物1：148.34～210.66℃；产物2：140.51～192.67℃；产物3：176.14～230.09℃；产物4：191.04～274.95℃；产物5：155.558～226.381℃；产物6：164.68～251.61℃，最后对比分析得出分子结构与其液晶性能间的关系。研究表明：（1）在分子结构框架类似的条件下，改变细微结构不会影响液晶化合物的晶型，只会影响其织构信息。（2）柔性链的嵌入会降低液晶化合物的熔点及清亮点，相变区间相应减小。（3）增加介晶基元的刚度会提高液晶化合物的熔点及清亮点，相变区间变化不大。（4）端基极性不同会影响其相转变温度，其影响是端基极性，氢键，空间效应综合作用的结果。更多还原

【Abstract】 Side Chain Liquid Crystalline Polymers Containing Azobenzene has great applicationprospect as functional materials in liquid crystal display、records storage medium,photoelectric conversion and so on. It is still an important part of current research thatdesigning and synthesizing new types of liquid crystal polymers to understand the relationshipbetween the structure and the properties of the liquid crystal. According to the Xinjiu Wangand Warner’s theory (W-W’s theory), the model of Side Chain Liquid Crystalline Polymerswith Azobenzene was designed. Then a series of Side Chain Liquid Crystalline PolymersContaining Azobenzene were got through the change of Flexible Space、Rigidity Unit andEnd Group in the structure of mesogenic unit: compound 1～6. Among them: compound 2had a longer flexible chain (-CH2CH2CH2O-) compare to compound 1; Compound 3 had onemore rigid benzene (Ar) compare to compound 2; Compound 4, compound 5 and compound 6had different end groups: SO3H、NO2、COOH respectively. The six compounds above hadprogressive relation in molecular design to research the influence between the molecularstructure changes and properties.The structure of the serie compounds were characterized by IR, then the texture wereobtained by Polarizing Observations Microscopic (POM), and found that they were allsmectic liquid crystal with different texture. Thermal properties (Tm-Ti) had been performedby using Differential Scanning Calorimeter (DSC), compound 1: 148.34～210.66℃;Compound 2: 140.51～192.67℃; Compound 3: 176.14～230.09℃; Compound 4: 191.04～274.95℃; Compound 5: 155.558～226.381℃; Compound 6: 164.68～251.61℃, finally therelationship between the molecular structure changes and properties were summarized.It showed that: (1) In the condition of similar molecular structure framework, the slightchange would not affect the crystalline form but the texture would be largely changed. (2) The embedded of the flexible chain would reduce the melting point and isolate point of the liquidcrystal compounds, and phase change interval would be reduced accordingly. (3) The increaseof the rigidity unit in liquid crystal compounds would raise the melting point and isolate point,but little change in phase change interval. (4) The different polarity of end group wouldinfluence the phase transition temperature, it was the combined affection of the end grouppolarity, hydrogen bond and the spatial effect.更多还原