This study reports the synthesis and characterization of two urethane dimethacrylates containing poly(ethylene oxide) or poly(propylene oxide) segment and cinnamate pendant moieties to be formulated in dental resin composites. H-1 NMR, C-13 NMR, and Fourier transform infrared spectroscopies, gel permeation chromatography, electrospray ionization-mass spectroscopy, and thermogravimetric measurements confirmed their structure, whereas the photopolymerization evolution of oligodimethacrylates relating to a low-molecular-weight dicinnamate methacrylate under ultraviolet irradiation was investigated by photo-differential scanning calorimeter, monitoring the degree of conversion (DC) and polymerization rate. The photopolymerization results reveal that the investigated derivatives display a good photoreactivity (DC: similar to 70%) during the formation of crosslinked polymers, the DC depending especially on the sample viscosity. The polymerization shrinkage for several mixtures including the urethane oligocinnamates (20 wt %) and diglycidyl methacrylate of bisphenol A/triethyleneglycol dimethacrylate system in the absence of filler was determined, the obtained values being in the range of 6.1-8.2 vol %. For few cured specimens incorporating quartz filler (75 wt %), water sorption/solubility, contact angle, and mechanical parameters were measured to establish if such monomers could be of interest in dentistry. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 127: 2442-2452, 2013