A matrix resin composition for fiber reinforced composite materials is described. The resin is thermosetting and achieves a glass transition temperature of at least 177° C. (Tg), obtained by curing at room temperature. The matrix resin will streamline composite fabrication processes by eliminating the need for heating during the cure process. The implications of this development are significant in terms of the ease of use and elimination of procedural steps. While the resin system was developed specifically for vacuum bagging, it is expected to be viable for other composite fabrication methods including resin transfer molding (RTM) and vacuum-assisted resin transfer molding (VARTM). The resin system is viable for use with carbon fiber reinforcements to fabricate laminates at least 0.20 inches thick. The resulting laminates have low porosity and mechanical properties equivalent to those prepared with common epoxy matrix resins.