Coplanar alignment of mesogenic moieties in a photocrosslinked liquid crystalline polymer film containing cinnamoyl groups

Coplanar alignment of mesogenic groups using polymer films of a methacrylate comprising a photocrosslinkable 4′-(2-cinnamoyloxyethoxy)-biphenyl group and a photoinactive 4-cyanobiphenyl group was realized by slantwise ultraviolet (UV) irradiation. Slantwise absorption measurement revealed that an orientational plane of the mesogenic groups was perpendicular to direction of the UV light propagation. The orientational angle and the ellipsoid of refractive index of the film could be regulated by changing the irradiation angle and degree of polarization of the UV exposure, respectively.