【作者】 郭凯；

【导师】 李自法； 郑世军；

【作者基本信息】 郑州大学 ， 材料学， 2002， 硕士

【摘要】 本论文主要内容有三部分： 对液晶和冠醚化合物的基本概念、分类、合成方法和表征方法作了简要的介绍，并着重说明了液晶冠醚的最新进展，进而阐述了我们的研究思路。 二．单体的合成与表征 从基础有机原料开始，合成了二苯并—14—冠—4、二苯并—18—冠—6、二苯并—15—冠—5及其二硝基、二氨基衍生物。通过NMR、IR、元素分析等手段对其结构进行了表征，对合成过程中出现的问题进行了讨论和解决，优化的合成方法。通过¹H-NMR、¹³C-NMR和分子力学计算法研究了二氨基二苯并冠醚异构体的空间立体结构。合成了另一种单体二醛化合物，通过¹HNMR、IR、元素分析等手段对其结构进行了表征。 三．Schiff碱型高分子液晶冠醚的合成与表征 从分子设计出发，设计了三类新的席夫碱型高分子液晶冠醚，根据分子中冠醚环的种类以及聚合物分子链构型的不同分为六个系列，共30个聚合物。以二氨基二苯并冠醚和二醛类化合物为单体，通过低温溶液聚合法合成了中等分子量的Schiff碱型液晶高分子。结构式如下所示： （A）系列Ⅰ和系列Ⅱ聚合物（含二苯并—14—冠—4的聚合物） （B）系列Ⅲ和系列Ⅳ聚合物（含二苯并—18—冠—6的聚合物） ［QO 口口口口L．————。口八＾旦。y。八 H ＝＝＝N、＿l＼l＼＿－N＝C－－We ／HOC（CH。）fort IkCfor u儿：问－Zi回＊：问－心回uD。：＊－oi卜＊：＊－＠ ＝＝N－＿l＼l＼＿＿e＝C－－－－ f－HCpe 回＊D． ＝＝N．＿歹＼I＼＿l 11 11“””11．O O。 lha ；＊－O n Hw ；＼－ H八 11＂＿八 ［I l——飞XY——一N＝＝＊一一（在一一OC（CH，）。CO一人’HC宁于 冈w一＊－二【瞩0人：＊－4；回Dw一＊－瓦瞩DV一＊－回 ＝＝N－Mol ＼l fW； l——飞 x 厂——一oCed rHCpe 回Iw．K）系列V和系列VI聚合物（含二苯并一15一冠一5的聚合物） I＿＿OO IMAs人 X 汀d一＼H 厂目＼IIJI 厂目＼HD ＝＝ Nry匕”xirtN“C’（ 人OC（CH，）。CO一人 人一C齐二 回人：＊－二；回wb：＊吕4；回w。：＊－历回VdZ＊－巴 回＊D．：＊曰二；回w＊＊曰4I回w＊＊曰句回V＊＊曰巴 DMbodHi－nHNryHI ＝＝N－－－－－ ILX“：1～ t－－m“Crt k－C4＝ Pv． PVIt 其化学结构经’H．NMR、IR和 GPC表征，利用偏光显微镜、DSC、TG和 WAXD对其热力学性能和液晶性作了研究。根据实验结果发现： （1）优化了二苯并一14一冠一4、二苯并一18一冠一6、二苯并一历一冠一5的合成方法，并首次合成了二术并一14一冠一4及二苯并一历一冠一5的二硝基、二氨基衍生物。（2）通过＊－NMR。13C－NMR和分子力学计算法研究了。is－DAmD814C4和 trans－DAmDB14C4的主间立体结构。发现＊－DAmDB14C4和 trans－DAmDB 14C4的 IHNMR谱图有明显区别，其立 2体结构分别近似属于 Ci和 CS群。（3）聚合物除Plla外都能形成液晶态，聚合物PIVc和PIVd能形成近晶相，其余的聚合物形成向列相．在液晶态呈现丝状和纹影织构，纹影织构的低阶向错和高阶向错共存。（4）聚合物液晶态丝状和纹影织构均可经降温在室温下长瑚保存。 （5）通过 GPC测得的含柔性间隔基聚合物的分子量在 10000以上，说明聚合方法是可行的。（6）在聚合物中，冠醚环的构象不同于相对应的小分于冠醚环的构象。两个苯环发生了相对扭曲，夹角变大，冠醚环变得舒展。 门）冠醚环和柔性间隔基对聚合物的热力学性能和液晶性能的影响是复杂的。随柔性间隔基K度的增加，玻璃化转变温度卜降，但柔性间隔基对熔点的影响是无规律的。 （8）聚合物5％热失重温度都在285C以上。更多还原

【Abstract】 This dissertation consists of three parts.1. The basic concept, classification, synthesis and characterization of liquid crystals and crown ethers were briefly introduced. The recent developments of liquid crystal polymers containing crown ethers were described. Moreover, our research plan were envisaged.2. Synthesis and characterization of monomersDibenzo-14-crown-4, dibenzo-18-crown-6,dibenzo-15-crown-5 and dinitryl, diamino substituted crown ethers were synthesized. The structures of these compounds were confirmed by means of NMR, 1R, elemental analysis and mass spectroscopy. The problems occurred in synthesis were discussed and dissolved. The synthesis processes were optimized. Moreover, the stereo structures of diaminodibenzo crown ethers were studied by means of ’H-NMR, 13C-NMR and molecular mechanics theory. Dialdehyde compounds were also synthesized and characterized.3. Polymerization and characterization of Schiff base type liquid crystal polymers containing crown ethersSchiff base type liquid crystal polymers containing crown ethers with high moderate weights were polymerized via low temperature solution polymerization. Their structures were shown in following schemes: (A) serieses I and II polymers containing DB14C4(B)serieses III and IV polymers containing DB18C6Their structures were confirmed by using 1H- NMR, IR and GPC. Thermodynamic properties and liquid crystal properties were studied by means of DSC, POM, TG and WAXD. According to the results of experiments it was found that:(1) Synthesis of compounds DB14C4, DB15C5 and DB18C6 were optimized and dinitro and diamino ramifications of DB14C4 and DB15C5 were synthesized first time.(2) The stereo structures of cis- and trans-diaminodibenzo-14-crown-4 in DMSO solvent have been investigated by 1HNMR,13CNMR and computer simulation. It was found that the stereo structures of cis- and /nms-diaminodibenzo-14-crown-4 in DMSO solvent approximatelybelong to groups Ci and Cs respectively.(3) All the polymers except polymer Plla could form liquid crystal phase. The polymers PIVc and PlVd went into smectic phase after being melted, the others went into nematic phase. Typical threaded and schlieren textures could be observed in liquid crystal phase. Both higher and lower rank distillations existed in schlieren texture.(4) Threaded texture and schlieren textures in liquid crystal phase could be maintained for a long time at room temperature by cooling.(5) The polymerization manner were practicable because the molecular weight of polymers determined by GPC were above 10000.(6) Conformations of crown rings of polymers were different from those of crown ethers, the two benzene rings of crown in polymers were contorted to each other.(7) The effects of crown ethers and soft units on polymers properties were sophisticated. Glass transition temperatures decreased with the length of soft units increasing, however, the effects of soft units were random.(8) 5% weight loss temperatures of all polymers were above 285.更多还原