Nematic Twin Molecules and their Application in Cholesteric Polymer Networks

The synthesis of some novel nematic twin molecules is described. The insertion of lateral substituents into the mesogenic core leads to glass forming materials. Cholesteric mixtures of nematic twins and a highly twisting sorbitol derivative were crosslinked by in-situ photopolymerization, whereby the LC-structure of the monomers is permanently fixed in the network. UV/VIS spectra of the networks were recorded to investigate the dependence of the reflection wavelength from the content of chiral monomer and from the polymerization temperature.