A polybenzoxazine/polysiloxane hybrid has been prepared by solgel process and ring-opening polymerization. For this purpose, first a functionalized benzoxazine was synthesized from bisphenol A, paraformaldehyde and 3-(trimethoxysilyl) propylamine, with initial molar ratio 1 : 4 : 2, and 95% yield. The structure of the monomer was characterized by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance. The solgel process and curing behavior have been studied by FTIR spectroscopy and differential scanning calorimetry. The dynamic mechanical thermal analysis of the hybrid material (Bz-PSi) showed higher Tg and storage modulus respect to the conventional polybenzoxazine (Bz-BA). Also, the thermogravimetric analysis revealed a better thermal stability. The high limiting oxygen index (LOI) values (about LOI = 32) confirmed similar effective flame retardance properties of the hybrid material respect to conventional benzoxazine. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012