Boron nitride nanosheets decorated by bismuth ferrite particles: preparation, characterization, and effect on flame-retardant performance of epoxy resin

Bismuth ferrite nanoparticle decorated boron nitride nanosheets (denoted as BF-BNNS) were first prepared as hybrid flame retardants by a hydrothermal route. The microstructure and morphology of the as-prepared BF-BNNS were investigated by x-ray diffraction, Fourier transform infrared spectrometry and transmission electron microscopy. Furthermore, the as-prepared BF-BNNS nano-fillers were incorporated into epoxy resin (EP) matrix of 3 wt% in order to reduce the fire risks of EP; and their effect on the flame-retardant performance and thermal stability of EP was examined by cone calorimetry and thermogravimetric analysis, respectively. Cone calorimetry test results show that BF-BNNS as the nano-fillers contribute to reduce the peak heat release rate, peak smoke production release, and toxic CO production of EP by 34.7%, 35.6%, and 50.0%, respectively, showing good flame-retardant ability. And thermogravimetry analysis presents that the as-prepared BF-BNNS/EP nanocomposite exhibits a high char yield at elevated temperatures in air and nitrogen. Besides, thermogravimetry analysis–infrared spectrometry tests show that the volatile products of BF-BNNS/EP such as hydrocarbon compounds, aromatic compounds and CO were suppressed significantly. This is because layered structure BNNS function as the physical barrier while BF with catalytic activity promotes the char formation, thereby effectively inhibiting the transfer and diffusion of heat and mass and significantly reducing the fire risks of EP. (paper)