Enhancing the water resistance properties of bamboo particleboard by reconstructing lignocellulose through carbonization treatment

Bamboo particleboards are recognized as a highly promising alternative to traditional wood particleboards owing to their short growth cycle, abundant availability, and exceptional mechanical properties. However, bamboo particleboards frequently exhibit undesirable hygroscopicity, which limits their broader applications. This study introduces a straightforward and inhibitor-free carbonization treatment method to enhance the water resistance properties of bamboo particleboards. During the carbonization process, the degradation of hemicelluloses and amorphous cellulose, combined with the condensation reactions among lignin molecules, leads to a significant reduction in the hydrophilic hydroxyl and carbonyl group content, resulting in a more compact micro-fibril structure. Concurrently, the degradation of specific macromolecules within the cell wall facilitates the crushing of bamboo during particleboard pressing, thereby reducing the macroscopic pore size between the particles in the board. When compared to the original bamboo particleboard, the moisture absorption, 24-h water absorption (at a relative humidity of 50 %), 24-h thickness swelling, and bound water content of the deep carbon bamboo particleboard decreased by 32.28 %, 81.57 %, 67.16 %, and 66.7 %, respectively, while the water contact angle increased by 88.89 %.