Styrene-containing mesogens. Part 1: photopolymerisable nematic liquid crystals
作者:Anthony Cook、Samer Badriya、Simon Greenfield、Neil B. McKeown
DOI:10.1039/b203940k
日期:2002.8.30
Several members of a novel series of styrene-containing liquid crystal monomers, based on the cyanobiphenyl mesogenic group, possess thermally stable nematic phases. These materials display a large odd–even effect, relating to the length of the flexible spacer between the styrene and cyanobiphenyl units, which is very similar to previously described liquid crystal ‘dimers’ composed of two cyanobiphenyl units. It is shown that styrene (i.e. 4-vinylphenoxy) is an excellent terminal group for cyanobiphenyl mesogens as compared to a number of other phenyloxy groups. In addition, a compatible bifunctional mesogenic crosslinker is described. Photopolymerisation of an aligned film of a low-melting eutectic mixture derived from these compounds is achieved using cationic initiation in aerobic conditions.
一系列基于氰基联苯致液晶基团的含苯乙烯液晶单体的成员,具有热稳定的向列相。这些材料表现出较大的奇偶效应,与苯乙烯和氰基联苯单元之间柔性连接链的长度有关,这一点与先前描述的由两个氰基联苯单元组成的液晶“二聚体”非常相似。研究表明,与其他多种酚氧基团相比,苯乙烯(即4-乙烯基苯氧基)作为氰基联苯介质的末端基团非常优秀。此外,还描述了一种兼容的双功能介质交联剂。通过在有氧条件下采用阳离子引发,成功实现了由这些化合物衍生的低熔点共晶混合物的对齐薄膜的光聚合。