Preparation Of Wood Fibers/Inorganic Nanoomposites And The Properties Of The Fiberboards

In this paper, three kinds of wood fiber/inorganic nanocomposites were produced by sol-gel technology with three different sols, in which the sols were pushed into cell walls of wood fibers though vacuum-soaking method. The structures of wood fiber/inorganic nanocomposites were characterized by IR, powder X-ray diffraction, Si NMR and SEM-EDX. The fiberboards from three kinds of wood fiber/inorganic nanocomposites were produced. The dimensional stability and fire-resisting properties of wood fiberboards were enhanced.The results of the research are showed as follows:1. In the process of preparing wood fiber/inorganic nanocomposites:vacuum filtration could help remove the sol that existed in the cell lumens and keep the porous structure of wood fiber composites; washing the surface with absolute ethyl alcohol could help remove the sol on the surface of fiber to keept bonding capacity.2. In the process of preparing wood fiber/SiO2 inorganic nanocomposites:when the mole ratio of H2O:TEOS was 30, WPG of the composites was the largest, and SEM and EDX showed that the mass fraction of silicon in the cell wall rose to 5.02%. FT-IR spectrum showed Si-O-Si had formed. XRD analysis showed the intensity of XRD peak of SiO2/wood fiber inorganic nanocomposites decreased.3. In the process of preparing wood fiber/Al2O3 inorganic nanocomposites:When PH=3.5-4.5, the sol was stable and transparent. The FT-IR spectrum showed O-Al-O had formed. SEM and EDX also showed that the nanoparticles had infiltrated into the cell wall of wood fiber. The mass fraction of Al in the cell wall was 5.72%.4. In the process of preparing wood fiber/SiO2-Al2O3 inorganic nanocomposites:when the mole ratio of H2O:TEOS was 50, WPG of the composites was the largest, and SEM and EDX showed that the mass fraction of Si was 5.02%, and the mass fraction of Al was 0.65% in the cell wall. The FT-IR spectrum showed Si-O-Si stretch vibration and O-Al-O vibration.5. Fiberboard samples were made through heat pressing with the three sol-treated wood fiber inorganic nanocomposites. It can be found that the dimensional stability and fire-resisting properties of wood fiberboards were enhanced. Among them, the comprehensive performances of the fiberboard from wood fiber/SiO2 inorganic nanocomposites were the best. TS was 16.9%, THR decreased to 15.1%, IB was 0.67Mpa, and MOR was 25Mpa.