Novel multifunctional photopolymers with both pendant epoxy groups and phenacyl ester groups were synthesized by the one-pot method for the reaction of poly(methacrylic acid) with epibromohydrin; this was followed by a reaction with phenacylbromide with 1,8-diazabicyclo- [5.4.0]undecene-7 as a condensation reagent. These esterification reactions proceeded smoothly and quantitatively under mild conditions. Moreover, the photochemical reactions of the resulting polymers were evaluated by UV and IR spectroscopy. The pendant phenacyl ester groups were photocleaved to give corresponding carboxyl groups, and then the produced carboxyl groups reacted with pendant epoxy groups. Furthermore, the baking process promoted a crosslinking reaction because of the addition reaction of epoxy groups with carboxyl groups after irradiation. It was also proven that the photochemical reactivity of the resulting polymers was affected by the structure of the phenacyl ester group. (C) 2001 John Wiley & Sons, Inc.