Eco-friendly wood composites with enhanced mechanical strength and flame retardancy

We developed a novel method for fabricating a wood composite with simultaneously enhanced mechanical strength and flame retardancy through integration of alginate and SiO2 nanoparticles. After the delignification of balsa wood, its porous structure was filled with a solution containing sodium alginate and sodium silicate. The resulting wood composite (termed hot-pressed flameretardant wood (HP-FRW)) was then obtained through the crosslinking of alginate, formation of SiO2 nanoparticles, and densification via hot-pressing. The HP-FRW exhibited high formability and an impressive tensile strength of 456 MPa, which is 7.4 times that of natural wood and 25 % higher than that of conventional densified wood produced through delignification and densification processes. Furthermore, the HP-FRW demonstrated excellent flame retardancy with selfextinguishing properties, which is hard to achieve simultaneously along with high strength by conventional methods.