Liquid-crystalline side chain polymers by chemical modification of poly(chloroalkylvinylether)s

The synthesis of polyalkylvinylethers with pendant 4-cyano-4'-oxybiphenyl groups gives thermotropic liquid-crystalline polymers. The new method developed here consists of the living cationic polymerization of chloroalkylvinylethers and the subsequent modification of the polymer by the mesogenic groups. The liquid-crystalline polymers have a controlled degree of polymerisation and narrow molecular weight distributions. The influence on the mesomorphic properties of various parameters such as the degree of polymerization, the spacer length and the proportion of the mesogenic side chain content has been investigated. Binary phase diagrams with low molar mass analogues are also reported and the properties of both neat materials and binary mixtures are compared.