Facile Construction of Inorganic Phosphorus/Boron-Layered Double Hydroxide Complexes for Highly Efficient Fire-Safety Epoxy Resin

For inorganic flame retardants, facile fabrication and high-efficiency fire safety without compromising the mechanical property of the matrix are still significant challenges. Here, nanolayered double hydroxide containing boron constructed on the surface of ammonium polyphosphate (APP) complexes (B-LDH@APP) is prepared by a simple in situ coprecipitation technology to reduce the fire hazard and improves the mechanical performances of epoxy resin (EP). The as-obtained 4B-LDH@APP/EP achieves the UL-94 V-0 rating and presents superior flame-safety performance. With respect to the 4APP/EP, the fire growth rate (FIGRA), the peak heat release rate (pHRR), and the peak smoke production rate (pSPR) of 4B-LDH@APP/EP decrease by 77.8, 57.3, and 52.6%, respectively. This is mainly attributed to the excellent synergistic flame-retardant effect among boron, LDH, and APP, which can accelerate the generation of compact charring residual with a good microstructure during combustion of B-LDH@APP/EP composites. Furthermore, B-LDH@APP slightly affects the mechanical performances of the EP matrix due to the upgraded interfacial interaction.