Three-component interpenetrating polymer network (IPN) matrix based glass fiber reinforced composites (GRC) have been prepared from the vinyl ester of an epoxy novolac resin (VEN), diglycidyl ether of bisphenol-A (DGEBA) (an epoxy resin), and methyl methacrylate (MMA) (a vinyl monomer). 2,2'-Azobisisobutyronitrile (AIBN) is employed as the initiator for both MMA and vinyl ester (VEN) resins, while DDM (diamino diphenyl methane) is employed for curing of DGEBA. All the IPNs and glass fiber reinforced composites based on these IPNs were characterized and are found to have good resistance to chemical reagents, good thermal stability, and good mechanical properties. (C) 2004 Wiley Periodicals, Inc.