含氟三联苯类异硫氰酸酯类液晶合成与微波性能研究  

Synthesis and microwave properties of fluorinated terphenyl isothiocyanate liquid crystals

作　　者：兰庚 曹秋豪 欧阳慧琦 张智勇 汪相如 高时汉 LAN Geng;CAO Qiu-hao;OUYANG Hui-qi;ZHANG Zhi-yong;WANG Xiang-ru;GAO Shi-han(Department of Chemistry and Environmental Engineering,Wuhan Polytechnic University,Wuhan 430023,China;School of Electronic Science and Engineering,University of Electronic Science and Technology,Chengdu 611730,China;Guangzhou Haige Communication Group Incorporated Company,Guangzhou 510663,China)

机构地区：[1]武汉轻工大学化学与环境工程学院,湖北武汉430023 [2]电子科技大学光电科学与工程学院,四川成都611730 [3]广州海格通信集团股份有限公司,广东广州510663

出　　处：《液晶与显示》2021年第9期1214-1224,共11页Chinese Journal of Liquid Crystals and Displays

基　　金：国家装发部预研基金项目(No.61409230701)。

摘　　要：近年来液晶在微波通信器件上的研究发展迅速,而液晶材料的介电损耗成为制约其发展的主要因素。异硫氰三联苯类化合物是一种结构稳定的低粘度、高双折射率液晶化合物,适于作为微波用液晶材料组分。本文通过偶联法合成了4种含氟三联苯异硫氰酸酯液晶化合物nPGUS(n=2~5),通过IR、^(1)H NMR、^(13)C NMR、^(19)F NMR确认化合物结构正确;差热分析(DSC)结果显示,它们都具有宽温向列相液晶态和相对较低的熔点,其中5PGUS的向列相温度范围达到101.8℃,熔点只有57.4℃;通过矩形谐振腔微扰法测试分析了它们在高频下的介电性能,将它们与母体液晶混合后,在18 GHz时的介电常数值(Δεr)为0.95,最大介电损耗为(tanδεr-max)0.00763,相位调制系数(τ)0.265,可满足微波用向列相液晶材料性能要求。In recent years,the research of liquid crystal in microwave communication devices has developed rapidly,and the dielectric loss of liquid crystal materials has become the main factor restricting its development.The isothiocyanate terphenyl compound is a low-viscosity,high-birefringence liquid crystal compound with stable structure,which is suitable as a component of liquid crystal material for microwave.In this paper,four fluorine-containing terphenyl isothiocyanate liquid crystal compounds nPGUS(n=2~5)were synthesized by coupling method,and the structure of the compounds was confirmed to be correct by IR,^(1)H NMR,^(13)C NMR,and ^(19)F NMR.Differential thermal analysis(DSC)results show that they all have a wide-temperature nematic liquid crystal state and a relatively low melting point.The nematic temperature range of 5PGUS reaches 101.8℃,and the melting point is only 57.4℃.Their dielectric properties of LC in the microwave K bands were tested by the vector network analyzer,and they are mixed with the matrix liquid crystal,the dielectric constant value at 18 GHz(Δεr)is 0.95,the dielectric loss(tanδεr-max)0.00763,dieletric tunability coefficient(τ)0.265,which can satisfy the performance requirements of nematic liquid crystal materials for microwave use.

关 键 词：含氟三联苯 异硫氰酸酯液晶 高介电常数 低介电损耗 合成 

分 类 号：O753.2[理学—晶体学] O69