Formation of H₂Ti₂O₅·H₂O nanotube-based hybrid coating on bamboo fibre materials through layer-by-layer self-assembly method for an improved flame retardant performance

In this study, H₂Ti₂O₅·H₂O nanotubes (TNTs) prepared through hydrothermal synthesis and TiO₂ used as a raw material were deposited on the surface of bamboo fibre materials through a layer-by-layer (LBL) self-assembly technique to reduce flammability. Scanning electron microscopy indicated that the TNTs were successfully loaded onto the bamboo surface, and their content was dependent on the number of assembled bilayers. Cone calorimetry results showed that the flame retardant performance of the coated bamboo fibre materials improved significantly. As the number of the assembled bilayers increased, performance was further enhanced. When the number of TNTs bilayers was 9, the time to ignition of the bamboo fibre materials was extended from 29.5 s for raw bamboo fibre (RBF) materials to 36.8 s for LBL9. The average heat release rate, total heat release and peak specific extinction area of the fibre materials decreased from 55.67 MJ/m² (RBF) to 35.28 MJ/m² (LBL9), and their fire performance index increased from 0.123 m² s/kW (RBF) to 0.161 m² s/kW (LBL9). Differential scanning calorimetry and thermogravimetry results demonstrated that the thermal oxidation and decomposition temperatures of bamboo fibre materials increased from 241.4 °C and 217 °C (RBF) to 311.3 °C and 274 °C (LBL9), respectively.