Carbazole terminal phenylene core imine skeletal nanosilica reinforced polybenzoxazine (nSi$${\mathrm O}_2$$/PBZ) hybrid nanocomposites

A new carbazole terminal nanosilica reinforced polybenzoxazine (nSiO2/PBZ) was synthesized using carbazole terminal benzoxazine monomer (CBZ) and nanosilica through in-situ sol-gel method. The FT-IR spectra were helped to confirm the formation of the hybrid nanocomposites. The PBZ-nSiO2 hybrids were accounted for their excellent thermal stability and good char yield due to the presence of the inter-cross linked silica networks in PBZ-nSiO2 hybrids. The high loading level of nanosilica particles into PBZ system elevated the glass transition temperature to a higher percentage than that of neat PBZ system. The hybrids obtained using high weight % of nanosilica (10 wt %) possessed higher Tg than that of hybrids prepared using low weight % nanosilica. The nSiO2/PBZ hybrids exhibited the higher thermal stability and the resultant higher char yield evidenced and proved from the TGA analysis. Transmission electron microscope and scanning electron microscope supported the morphological features of the homogeneous dispersion of the inorganic nanosilica in the polybenzoxazine matrix.