The heat insulation and smoke suppression effect of M-Si-phosphocarbonaceous catalyzed by metal salt-doped APP silicon gel in situ build in wood

Wood is favored by furniture and decorative materials due to its beautiful color and texture, lightweight and high strength, but the thermal stability and flame retardants of wood have not been well solved. In this paper, metal salt-doped ammonium polyphosphate silicon gel (Cu, Mn/APP/Gel) was trapped in the wood cell wall and cell cavity by vacuum-pressure infusion method and vacuum drying method. Compared with unmodified wood, Cu, Mn/APP/Gel impregnated wood can rapidly enhance the flame retardant and smoke suppression capability of wood due to the catalysis of Cu2+ and Mn2+, and the total heat release rate, heat release rate peak value, mean heat release rate, smoke produce rate, total smoke release, CO and CO2 yield (YCO, YCO2) are obviously reduced. The electronic microscope picture of the burned carbon layer shows that the Cu, Mn/APP/Gel doped wood no longer has a clear and beautiful carbon layer formed by cell structure, but completely forms a whole. It is this dense and firm carbon layer structure that effectively inhibits the thermal decomposition of wood and has a role in flame retardant and smoke suppression. This study proposed an environment-friendly and green scheme for flame retardant modification of wood.