A new epoxy resin with high glass transition temperature (Tg) (similar to 180 degrees C) and a viscosity low enough for infiltration into dry reinforcements at 40 degrees C was developed for the vacuum-assisted resin transfer molding process. To study the curing behavior and viscosity, several blends were formulated using multifunctional resin, aromatic hardener, and reactive diluents. Effects of these components on the viscosity and Tg were investigated by thermomechanical analysis, dynamic scanning calorimetry, and rheometer. Experimental results showed that a liquid aromatic hardener and multifunctional epoxy resin should be used to decrease the viscosity to <1 Pa.s at 40 degrees C. Moreover, the addition of a proper reactive diluent decreased the viscosity and simultaneously minimized the deterioration of Tg. Mechanical properties of the composite produced with the optimized blend were evaluated at both room-temperature and high-temperature conditions. According to the results, the composite showed comparable mechanical properties with that of the current commercial resin. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013