近晶C(Sc)相串型液晶高分子的合成与表征

以２，５ 二（对烷氧基苯甲酰氧基） 对苯二酚和不同结构的脂族二酰氯为单体，采用低温溶液缩聚的方法，合成了一系列新的液晶基元垂直于分子主链的Ｓｃ相串型液晶高分子．单体的结构通过元素分析、ＩＲ、１Ｈ ＮＭＲ和ＭＳ等方法确证．聚合物通过ＧＰＣ、ＤＳＣ、ＴＧ、ＷＡＸＤ和偏光显微镜等方法测试表征．研究发现，所有的聚合物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纹影或焦锥织构．通过变温Ｘ 射线衍射证明它们为Ｓｃ相．所有聚合物的熔点（Ｔｍ）和液晶态的清亮点（Ｔ１）随分子中末端烷氧基增大和柔性间隔段长度增加逐渐降低，液晶态温度范围变窄．

SYNTHESIS AND CHARACTERIZATION OF SEMETIC C PHASE LIQUID CYSTAL POLYMERS WITH MESOGENIC LATERALLY FIXED ONTO THE MAIN CHAIN

A new series of semetic C phase liquid crystal polymers with mesogens laterally fixed onto the main chain was synthesized via low temperature solution polycondensation from 2,5 bis(p alkoxyl benzoloxy) hydroquinone and aliphatdiyl chloride with different structure.The low molecular weight compounds were analyzed by elemental analysis IR 1H NMR and MS.The polymers were characterized by GPC DSC TG WAXD and polarizing microscope with heating stage.It was found that all the polymers went to liquid crystal phase when heated to their Tm.The Schlieren texture or focal conic texture can be observed.Temperature variable X ray diffraction realized that they are smectic c phase.Both Tm and T i of all the polymers decreased with the increase of the end alkoxy group length and the flexible spacer unit in the polymers gets longer,the temperature range of the liquid crystal phase of the polymers becomes narrow.