Development of flame-retardant bamboo particleboards using bio-based adhesives and ammonium polyphosphate

With the growing depletion of sustainable forest resources, bamboo has attracted increasing interest as a rapidly renewable material with robust mechanical strength. However, bamboo-based composites are inherently flammable, and conventional adhesives often release formaldehyde. This study developed a flame-retardant bamboo particleboard by incorporating ammonium polyphosphate (APP) into a bio-based adhesive system. APP formed phosphate–hydroxyl interactions with the adhesive and provided effective pore filling within particle gaps, thus enhancing both flame retardancy and mechanical properties. The optimized particleboard (ABP15) achieved an internal bonding strength of 1.14 MPa, far exceeding the standard requirement. Moreover, ABP15 reached a LOI of 32.48 % and attained a UL-94 V-0 rating, while peak heat release rate and smoke production rate were reduced by 44.9 % and 38.5 %, respectively. Raman and TG-IR analyses confirmed the formation of a denser and more stable char layer at the adhesive–bamboo interface. Overall, this study demonstrates a straightforward approach for developing eco-friendly bamboo composites with improved fire safety and mechanical reliability.