Optical anisotropy of chalcone-based epoxy compound under irradiation of linearly polarized UV light

Photocrosslinkable chalcone-epoxy compound comprising 1,3-bis-(4-hydroxy-phenyl)-propenone was synthesized for studying the optically induced anisotropy of the thin films. Chalcone group was introduced into the main chain unit of the epoxy oligomer. We observed a photodimerization behavior and an optical anisotropy of this material by irradiation of linearly polarized UV light (LPL). With a trace amount of cationic photoinitiator, polymerization of epoxy groups was also conducted at the similar wavelength range used for photodimerization. Optical anisotropy of the thin film was also investigated by using polarized FT-IR and UV absorption spectroscopy either with or without cationic photoinitiator. Two kinds of photochemical reaction were employed to enhance the anisotropy using the chalcone-epoxy compound.