Hierarchical Lamellar Aluminophosphate Inorganic Materials for Medium Density Fiberboard with Good Fire Performance

Fire safety issues have attracted much attention since they cause enormous loss of lives and properties. In this study, the sustainable aluminophosphate (AP) adhesive is developed as a fire retardant for improving the fire performance of medium-density fiberboard (MDF). The properties of AP adhesive and AP-based MDF were evaluated based on a scanning electron microscope, thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and cone calorimetry. The thermostability and fire performance of MDF are significantly improved by the deposition of the AP inorganic layer on the wood fibers surface, which could protect wood fibers from further oxidation and take away part of the heat. Compared to control sample (UF sample), the pkHRR (151.7 kW m−2), THR (66.0 MJ m−2), TTI (21 s), and mean EHC (14.6 MJ kg−1) of AP-based MDF was reduced by 52.7%, 39.0%, 41.7%, and 32.8%, respectively. Also, the existence of the AP inorganic layer is beneficial to netting the solid phase and volatile flammable components in char residue of MDF, resulting in large mass loss rate, off-gases (CO and CO2) release and smoke suppression properties. Therefore, AP could improve the fire performance of MDF.