对联苯乙炔类液晶单体的紫外稳定性进行了研究。实验数据显示: 经紫外照射200 min后，液晶的阈值电压降低，折射率减小。液晶化合物的UV降解不仅与吸收波长有关，而且还与分子结构有关。本文分析了末端官能基团以及连 接基团对此类单体紫外稳定性的影响: 联苯乙炔与末端基团为NCS官能团连接的化合物的UV稳定性要优于与CN连接的化合物; 并且当以1,4-环己基作为连接基团时化合物的UV稳定性要好于酯基(-COO-)作为连接基团和没有连接基团的化合物。

The UV stability of liquid crystal compounds containing tolane group was studied.It showed that the threshold voltage and birefringence of the liquid crystal decreased after 200 minutes of UV exposure. And it indicated that UV degradation of the liquid crystal depended on not only the absorption wavelength but also the detailed molecular constituents.The UV stability of liquid crystal with different terminal groups and linking groups were analyzed.The measured data showed that the diphenyl acetylene compounds with NCS terminal group exhibited a better UV stability than those with CN terminal group.The compounds with 1,4-cyclohexyl linking group were better than those with -COO- linking group or with none linking group.