一系列新的席夫碱型液晶高分子冠醚的合成与表征  

SYNTHESIS AND CHARACTERIZATION OF A SERIES OF NOVEL SCHIFF BASE LIQUID CRYSTALLINE POLYMER CROWN ETHERS

作　　者：李自法[1] 郭凯[1] 张晓静[1] 张腾[1] 郑世军[1] 张淑媛[2] 周其凤[3] 李磊[3] 

机构地区：[1]郑州大学材料工程学院,郑州450052 [2]郑州大学化学系,郑州450052 [3]北京大学化学院高分子科学与工程系,北京100871

出　　处：《高分子学报》2003年第2期175-179,共5页Acta Polymerica Sinica

基　　金：国家自然科学基金资助项目 (基金号 2 99740 2 6);河南省自然科学基金;河南省教育厅自然科学基金资助项目

摘　　要：以 4,4′ (α,ω 烷亚甲基二酰氧 )二苯甲醛和二氨基二苯并 1 5 冠 5为单体 ,采用溶液缩聚方法 ,合成了一类新的席夫碱型液晶高分子冠醚 .一种单体采用脂族二酰氯和对羟基苯甲醛反应制备 ,另一种新的单体采用二硝基二苯并 1 5 冠 5 ,在钯 碳催化剂存在下 ,水合肼还原制备 .合成的二硝基和二氨基 二苯并 1 5 冠 5 ,未能从IR和1 H NMR谱图上区分它们的几何异构体 .聚合物的分子量不高 ,Mn 在 1 0 1 0 0～ 1 3 0 0 0之间 .单体的结构通过元素分析、IR、1 H NMR和MS等方法确证 .聚合物的性质采用GPC、DSC、TG和POM等方法进行了研究 .发现所有的聚合物加热到各自的熔融温度 (Tm)以上都能形成液晶态 ,在液晶态可以观察到向列相的丝状织构和纹影织构 .聚合物的玻璃化转变温度 (Tg)、熔融温度和各向同性温度 (Ti)随聚合物分子中柔性间隔基的变化而变化 ,它们有较高的清亮点温度和宽的液晶态温度范围 .A novel series of Schiff base type polymer liquid crystalline crown ethers was synthesized for the first time by solution polycondensation from 4,4'-(alkylene dioyloxy) dibenzaldyhyde (M-1) and diamino-dibenzo-15-crown-5 (M-2) as the monomers. Monomer M-1 has been synthesized by esterification reaction of aliphatdiyl chloride and 4-hydroxybenzaldehyde. Monomer M-1 has been synthesized by reduction reaction of dinitrodibenzo-15-crown-5 in the presence 10% Pd/C catalyst and hydrazine hydrate. The geometric isomers of dinitrodibenzo-15-crown-5 and diaminodibenzo-15-crown-5 that were synthesized for the first time can not be differentiated by IR spectrum and H-1-NMR spectrum. The molecular weights of the polymers are not high, and the M-n of the polymers ranges from 10100 similar to 13000. The monomer structures were identified by using elementary analysis, IR, H-1-NMR and MS etc. The properties of polymers were investigated by using GPC, DSC, TG, WAXD and POM. It was found that all the polymers went into a liquid crystal phase when heated to their melting temperature (T-m). The threaded texture and schlieren texture can be observed. The glass transition temperature (T-g), melting temperature and isotropization temperature (T-i) change with varing the flexible spacer unit in the polymers, all the polymers have higher clearning points and wide mesophase ranges. The WAXD study illustrated that the polymers of 6 I-a, 6 I-c, 6 IIb, and 6 IId are liquid crystalline with a nematic phase. A dispersive peak at 2theta near 20degrees appeared on their WAXD curves, which is a typical character for quenched nematic liquid crystal polymers.

关 键 词：席夫碱 液晶高分子冠醚 合成 表征 分子结构 4 4’-(α w-烷亚甲基二酰氧)二苯甲醛 二氨基二苯并-15-冠-5 

分 类 号：O753[理学—晶体学]