1997 Volume 10 Issue 1 Pages 13-17
The photopolymer material of poly(vinyl cinnamate) (PVCi) has been used to align liquid crystal molecules using linearly-polarized UV light, and the LC alignment mechanism on the films has been investigated. Comparing the LC alignment on rubbed PVCi films with that on UV-exposed PVCi film, it is shown that the side chains of PVCi molecules strongly interact with the LC molecules on the PVCi films and thus the alignment mechanism on linearly-polarized UV-exposed PVCi films is due to the anisotropic van der Waals interaction between LC molecules and optically-anisotropic PVCi films arising from the photo-induced anisotropic side chain distribution on the films. We also study the thermal stability of UV- exposed PVCi films, and clarify the improvement of the thermal stability with increasing UV exposure energy.
