Synergistic preparation of environmentally friendly flame-retardant high-strength timber through biomimetic mineralization and densification

Wood, a sustainable building material, faces limitations due to its inherent low mechanical strength and flammability. This study develops a biodegradable, high-strength, and flame-retardant wood composite through a synergistic strategy combining sodium alginate-induced biomimetic mineralization of calcium carbonate with physical densification. The resulting material achieves a limiting oxygen index of 31.5%, meeting the standard for high-performance flame-retardant materials. Its specific modulus reaches 28.26 GPa·cm³·g⁻¹, surpassing that of aluminum. Notably, cone calorimetry analysis reveals a synergistic suppression of smoke production. Environmental evaluations confirm the composite retains excellent biodegradability and exhibits low ecotoxicity. Utilizing industry-compatible processes and low-cost raw materials, this approach offers a scalable and practical pathway for producing advanced bio-based construction materials.