The effects of two nonreactive conventional-type resins, a bisphenol-Abased phenoxy resin PAPHEN-301 and aromatic-based PETROLEUM RESIN, on the mechanical, thermal, and physical properties of methacrylated urethane resin-based W-curable formulations were studied. A methacrylated urethane prepolymer was synthesized from isocyanatoethyl methacrylate (IEM) and polytetrahydrofurandiol (PTHF) via a one-step reaction. An increase in PAPHEN-301 content caused an increase both in tensile strength and elongation values of UV-cured polymeric films. On the other hand, an increase in PETROLEUM RESIN content caused a decrease both in tensile strength and elongation values of the polymeric films. However, thermooxidative properties were not affected by the introduction of either resin. It was also found that the water-absorption capacities of the UV-cured methacrylated urethane films depended on the type and amount of the nonreactive resins. (C) 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1831-1845, 1998.