Vinyl-terminated benzoxazine (VB-a), which can be polymerized through ring-opening polymerization, was synthesized through the Mannich condensation of bisphenol A, formaldehyde, and allylamine. This VB-a monomer was then blended with epoxy resin and then concurrently thermally cured to form an epoxy/VB-a copolymer network. To understand the curing kinetics of this epoxy/VB-a copolymer, dynamic differential scanning calorimetry measurements were performed by the Kissinger and Flynn-Wall-Ozawa methods. Fourier transform infrared (FTIR) analyses revealed the presence of thermal curring reactions and hydrogen-bonding interactions of the epoxy/VB-a copolymers. Meanwhile, a significant enhancement of the ring-opening and allyl polymerizations of the epoxy was observed. For these interpenetrating polymer networks, dynamic mechanical analysis and thermogravimetric analysis results indicate that the thermal properties increased with increasing VB-a content in the epoxy/VB-a copolymers. (C) 2010 Wiley Periodicals, Inc. Appl Polym Sci 117: 3121-1127, 2010