苯基异硫氰酸酯类液晶材料的稳定性  

Stability of phenyl-isothiocyanate liquid crystal materials

作　　者：彭增辉[1] 刘永刚[1] 穆全全[1] PENG Zenghui;LIU Yonggang;MU Quanquan(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《液晶与显示》2024年第11期1431-1436,共6页Chinese Journal of Liquid Crystals and Displays

基　　金：国家重点研发计划(No.2021YFB3600300)。

摘　　要：苯基异硫氰酸酯化合物可制成向列相液晶材料。这类材料不仅具有高双折射率,还具有低黏度的特性,在液晶光学器件中应用时可实现快速响应。然而,这类液晶材料存在稳定性问题,导致其制成的液晶器件无法长时间稳定运行。本文研究发现,在加速老化实验中,100℃处理1000 h后,该材料的双折射率下降了8.5%。通过高效液相色谱法和质谱法分析,确认羟基化合物会引起异硫氰酸酯基团的离解,导致材料稳定性欠佳。最后,在设计的无水环境下进行老化实验,结果显示材料的降解程度大幅降低,在相同条件下双折射率仅下降1.1%。本研究为这类材料的应用提供了重要的指导方案。Phenyl isothiocyanate compounds can be used to produce nematic liquid crystal materials with high birefringence.These materials can simultaneously possess high birefringence and low viscosity,and can achieve rapid response in liquid crystal optical devices.However,this type of liquid crystal material is considered to have stability problems,and it is believed that the liquid crystal devices made from it cannot maintain stable operation for a long time.This study found that in accelerated aging experiments,the birefringence of the material decreased by 8.5%after 1000 h of treatment at 100℃.Then,the reasons for the poor stability of isothiocyanate liquid crystal compounds were analyzed by high-performance liquid chromatography and mass spectrometry,confirming that hydroxyl compounds can cause the dissociation of isothiocyanate groups.Finally,the stability of the material was tested in the designed anhydrous environment,and it was shown that the degradation degree of the material was significantly reduced,with a decrease in birefringence of 1.1%under the same conditions.The research in this paper will provide some guidance for the application of such materials.

关 键 词：液晶材料 异硫氰酸酯 高双折射率 稳定性 

分 类 号：O753.2[理学—晶体学] TN141.9[电子电信—物理电子学]