Dye-containing S∗_c side-on/end-on copolymers

Abstract

Mesomorphic copolysiloxanes, which combine ‘normal’ end-on linked chiral mesogenic units inducing S∗_c phases and side-on fixed chromophores were prepared. The interplay of the different orientational tendencies of these moieties, which are perpendicular (end-on linked mesogenic groups) or parallel (side-on fixed chromophores) to the polymer chain, lead to a strong destabilization of the S∗_c phase. However, copolymers with up to about 10 mol % of chromophores still show a smectic C∗ phase. FTIR measurements show that both moieties orient parallel to each other and perpendicular to the polymer chains. These copolymers are interesting to consider as coloured guest-host S∗_c materials for coloured displays or as pyro-electric detectors.