Hydrogenated rosin epoxy methacrylate (HREM), based on hydrogenated rosin and glycidyl methacrylate (GMA), was synthesized for use as an advanced tackifier in the UV-crosslinking pressure sensitive adhesives (PSAs) system. The HREM, as a tackifier, contained UV-Curing sites; thus, allowed photopolymerization to occur by UV irradiation. This UV-curable tackifier, HREM, can improve the curing rate and adhesion performance of UV-crosslinking PSAs. The characteristics of HREM were analyzed by GPC and DSC and its synthetic mechanism studied using FTIR and H-1 NMR; the characteristic peaks of hydrogenated rosin and GMA vanished, but new peaks for HREM appeared. The PDI and the T-g by DSC were 1. and -25.6 degrees C, respectively. The photopolymerization of HREM was Studied using photo-DSC. Heat flow was observed during UV irradiation, and the curing rate and conversion both increased with rising photoinitiator content. (c) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 1172-1176, 2009