Sustainable particleboard from bamboo waste/water hyacinth/plant-based polyurethane adhesive composite: a green flame-retardant material

This research investigates creating sustainable particleboards using natural fibers as affordable resources. Bamboo shavings (BS), a byproduct from furniture manufacturing, and water hyacinth (WP), an invasive aquatic plant, served as raw materials. The boards were produced by mixing BS and WP in different ratios (0–100%) and bonding them with castor oil-based polyurethane adhesive. To improve fire resistance, a bio-based flame-retardant system was added, using water hyacinth as a carbon source. Mechanical tests showed that BS100 panels had the highest modulus of elasticity (9,803 MPa) and internal bond strength (0.68 MPa), whereas WP-rich panels (≥75%) had lower values, with MOE as low as 4,266 MPa and IB strength at 0.30 MPa. Only BS100, WP25, and WP50 panels met EN 312 (Type P5) standards for load-bearing use. Fire tests revealed that panels with water hyacinth achieved a UL94 V-0 rating, indicating good flame-retardant properties. Increasing WP content decreased the net heat of combustion, thus enhancing fire safety, while higher BS content boosted structural strength. Overall, 50% WP provided an optimal balance, offering improved flame resistance with adequate mechanical performance. This study emphasizes the potential of utilizing waste bamboo and invasive species to develop eco-friendly, fire-resistant building materials.