Application Of Montmorillonite(MMT) In Chinese Fir Treated With Copper-ethanolamine

In order to improve the defects of water-borne preserved wood, such as mechanical properties, the two-step method was used in this research to prepare Chinese fir/Montmorillonite(MMT) water-borne preservative composite through introducing copper-ethanolamine(CuEA) and MMT intro Chinese fir separately, and the didecyl dimethyl ammonium choride(DDAC) was used as the intermediate medium to introduce MMT into wood, the influence of different copper to amine mole ratio(1:2, 1:4, 1:6) and MMT to the properties of preserved wood was analyzed. The structure of Chinese fir/Montmorillonite(MMT) water-borne preservative composite was characterized by the X-ray Diffraction(XRD), Fourier Transform Infrared spectrum(FTIR) and Scanning Electron Microscope(SEM), the surface hardness, compression strength parallel to grain, contact angle and leaching resistance of copper were tested and analyzed referring to relevant standards. The following results were obtained:â‘ the retention rate of CuEA, surface hardness and compression strength parallel to grain of preserved wood increased as the copper to amine mole ratio increasing; the copper fixation of preserved wood increased as the copper to amine mole ratio increasing( copper fixation decreased when the ratio was more than 1:4, because ethanolamine in solution will compete for the adsorption sites with copper ion when the copper to amine ratio was too high), the contact angle increased as copper fixation increasing because the fixation of copper can increase the water repellence of wood surface; the leaching resistance of copper decreased as copper to amine mole ratio increasing. Copper to amine mole ratio 1:4 was suggested through comprehensive evaluation.â‘¡the surface hardness, compression strength parallel to grain and contact angle of Chinese fir/Montmorillonite(MMT) water-borne preservative composite was increased because of the filling effect of MMT to free space of wood, especially the wood surface; the introduction of MMT into preserved wood didn't increase leaching resistance of copper, because the bonding force between MMT and wood cell wall was weak, MMT can be leached out from wood cell wall easily through water-leaching, the components of CuEA adsorbed by the MMT layers can be easily leached out accordingly.â‘¢XRD analysis shows that CuEA and MMT didn't change the crystal structure of preserved wood; FTIR shows that CuEA mainly reacted with carboxyl group comes from hemicellulose, and there was no chemical reaction happened between MMT and wood components; SEM analysis shows that, MMT mainly distributed in the tracheid, pit, ray tracheid and its adjacent tracheid, which suggested that the tracheid, pit, and ray tracheid were the main permeability channels for MMT in Chinese fir.