Structurally Designed Imine Skeletal Pyrenyl Pendant Pyridine Core Polybenzoxazine nSiO2/PBZ Hybrid Polymer Nanocomposites

Abstract

Novel polybenzoxazine-silica (nSiO2/PBZ) hybrid nanocomposites were designed and synthesized using carbazole terminal pyrenyl pyridine core imine skeletal benzoxazine monomer (PYCBZ) and nanosilica (nSiO2) through in situ sol-gel method. The FT-IR and Raman spectral studies ascertained the formation of nanosilica reinforced polybenzoxazine hybrid nanocomposites. The nSiO2/PBZ hybrid nanocomposites exhibited excellent thermal stability and higher char yield than that of neat PBZ. The elevation in glass transition temperature of the nanocomposites was evidenced by the limited motion of the polymeric network with the introduction of nanosilica particles in the PBZ matrices. The hydrophobic nature of a less polar nSiO2 in the composites zipped the water uptake behaviour of (nSiO2/PBZ) hybrid nanocomposites to low percentage. The shift in the absorption peak reveals that the nanosilica particles were successfully incorporated through thermal ring opening polymerization of benzoxazine. The homogeneous reinforcement of nSiO2 particles retains the fluorescent properties of polybenzoxazine. The uniform molecular level dispersion of nano SiO2 onto polybenzoxazine networks were confirmed from transmission electron microscope and scanning electron microscope images.