Liquid crystal alignment properties of polystyrene derivatives containing coumarin side groups

The liquid crystal (LC) alignment properties of LC cells fabricated with films of polystyrene derivatives containing coumarin side groups (P7COU#, where # is the molar content of coumarin side groups in %) were investigated. Good optical transparency of the P7COU# films was observed in the visible light region. LC cells fabricated with rubbed P7COU# films with more than 51mol.% of coumarin-containing monomeric units exhibited LC alignment perpendicular with respect to the rubbing direction with a high azimuthal anchoring energy (1 x 10(-5) -7 x 10(-5) Jm(-2)). LC cells made from rubbed P7COU# films with more than 65mol.% of coumarin-containing monomeric units exhibited a shift of the LC alignment direction by approximately 10 compared with those made from a polystyrene film. The electro-optical performance of the LC cells fabricated with the rubbed P7COU82 film was found to be as good as that of the LC cells fabricated with a rubbed polyimide film.