Photochemically bifunctional epoxy compound containing a chalcone moiety

A new bifunctional epoxy compound was synthesized by the reaction of 4,4′-dihydroxychalcone and epichlorohydrin. Photosensitivity of the synthesized chalcone–epoxy compound was investigated by using UV–visible and Fourier transform infrared spectroscopies. The result of spectroscopic analysis substantiated that the chalcone–epoxy compound has functions of both crosslinking and cationic polymerization by UV exposure (λ=300–360 nm). Photodimerization of the chalcone–epoxy compound was confirmed by UV–visible and IR absorbance changes of the CC double bond of the chalcone unit. A small amount of onium salt as a photoinitiator could facilitate the cationic photopolymerization of the chalcone–epoxy compound by UV exposure. The UV-cured chalcone–epoxy compound showed an excellent thermal stability as compared to the conventional UV-cured bisphenol A type epoxy resin.