Synthesis and characterization of polybenzoxazine containing phosphorus

The novel benzoxazine monomer containing phosphorus has been synthesized based on multifunctional amine route from bis(4-aminophenyl)phenylphosphate, p-cresol and formaldehyde. Subsequently, the benzoxazine monomer was thermo-cured into polybenzoxazine containing phosphorus. The chemical structures were identified by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR). The curing reaction was monitored by differential scanning calorimetry (DSC) and FT-IR. The thermal and flame-retardant properties of obtained polybenzoxazine were evaluated by dynamic mechanical thermal analysis (DMA), thermal gravimetric analysis (TGA) and oxygen index meter, respectively. The results show that the novel polybenzoxazine has high limiting oxygen index (38.1) and glass transition temperature (232°C).