Effects of Nanofillers on Water Resistance and Dimensional Stability of Solid Wood Modified by Melamine-Urea-Formaldehyde Resin
Keywords:
Water absorption, dimensional stability, wood polymer composites, solid wood, nanocompositesAbstract
The water absorption and dimensional stability of wood impregnated with melamine-ureaformaldehyde (MUF) and wood impregnated with different nanofiller/MUF formulations were investigated. Three kinds of nanoparticles, Cloisite® 30B, Claytone® APA, and Cloisite® Na+, were selected and mixed with MUF resin, and subsequently impregnated into solid aspen wood through a vacuum and pressure process. The wood polymer nanocomposites were prepared by in situ condensation polymerization of the impregnated wood under specific conditions. Significant improvements in water repellency and better dimensional stabilities were obtained for the nanofiller/MUF-treated wood. The untreated wood absorbed around 63% of moisture after 24 h soaking in water, while water uptake was about 125% after 1 week immersion in water. The MUF resin-impregnated wood absorbed about 8.3% and 38.5% of moisture after 24 h and 1 week immersion in water, respectively. For the organophilic nanoclay/MUF resin-impregnated wood, much lower water absorption in the amounts of around 5% water uptake in 24 h and 22% after 1 week was observed. The antiswelling efficiency (ASE) was also improved from 63.3% to 125.6% for the nanofiller/MUF-treated wood. The significant improvement in water resistance and dimensional stability of the resulting wood polymer nanocomposites can be attributed to the introduction of MUF and nanofillers into the wood. X-ray fluorescence shows that some nanoparticles have migrated into the wood cell wall. Wood treatments with MUF and nanofiller/MUF showed no significant influence on the color of the wood, which is important for practical application of the treated wood in some specific areas such as flooring.References
American Society for Testing and Materials (ASTM). 1999. Standard Test Methods for Evaluating Properties of Wood-Base Fiber and Particle Panel Materials. D 1037-99, American Society for Testing and Materials, West Conshohocken, PA.nAyer, S. W., D. Fell, and H. Wan. 2003. Hardening of solid wood: Market opportunities and review of existing technologies. Forintek Canada Corp., Québec, Canada.nByun H. Y., M. H. Choi, and I. J. Chung. 2001. Synthesis and characterization of resol type phenolic resin/layered silicate nanocomposite. Chem. Mater.13:4221-4226.nCai X., B. Riedl, S.Y. Zhang and H. Wan. 2007. Formation and properties of nanocomposites made up from solid aspen wood, melamine-urea-formaldehyde, and clay. Holzforschung.61:148-154.nCai X., B. Riedl, S.Y. Zhang and H. Wan. 2006. Effect of Nanofiller on the Performance of Wood/Melamine-Urea-Formaldehyde Nanocomposites, BioPlastics Montreal, September 27-29, 2006, Montreal, Canada.nDeka M., and C. N. Saikia. 2000. Chemical modification of wood with thermosetting resin: Effect on dimensional stability and strength property. Bioresource Technol.73:179-181.nGalperin A. S., G. G. Kuleshov, V. I. Tarashkevich, and G. M. Shutov. 1995. Manufacturing and properties of modified wood: A review of 25 years work. Holzforschung49:45-50.nGilman, J. W. 1999. Flammability and thermal stability studies of polymer layered-silicate (clay) nanocomposites. Appl. Clay Sci.15:31-49.nGindl W., and H. S. Gupta. 2002. Cell-wall hardness and Young's modulus of melamine-modified spruce wood by nano-indentation. Composites Part A33:1141-1145.nHartley I. D., and M. H. Schneider. 1993. Water vapour diffusion and adsorption characteristics of sugar maple (Acer saccharum, Marsh.) wood polymer composites. Wood Sci. Technol.27:421-427.nKim, M. G. 2001. Examination of selected synthesis parameters for wood adhesive-type urea-formaldehyde resins by 13C NMR spectroscopy. III. J Appl. Polym. Sci.80:2800-2814.nKojima, Y., A. Usuki, M. Kawasumi, A. Okada, T. Kurauchi, and O. Kamigaito. 1993. Sorption of water in nylon 6-clay hybrid. J. Appl. Polym Sci.49:1259-1264.nKumar, S. 1994. Chemical modification of wood. Wood Fiber Sci.26(2):270-280.nQutubuddin, S., and X. Fu. 2002. Polymer-clay nanocomposites: Synthesis and properties. Pages 653-673 in M. Rosoff, ed. Nano-Surface Chemistry. Marcel Dekker Inc., New York, NY.nRay, S. S. and M. Okamoto. 2003. Polymer/layered silicate nanocomposites: A review from preparation to processing. Prog. Polym. Sci.28:1539-1641.nRowell, R. M. 1983. Chemical modification of wood. For. Prod. Abstr.6(12):363-382.nSchadler, L. S. 2003. Polymer-based and polymer-filled nanocomposites. Pages 77-154 in: P. M. Ajayan, L. S. Schadler, and P. V. Braun eds. Nanocomposite Science and Technology. WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany.nSchneider, M. H. 2001. Wood-polymer composites. Pages 9764-9766 in K. H. J. Buschow, R. C. Flemings, B. Ilschner, E. J. Kramer, and S. Mahajan, eds. The Encyclopedia of Materials: Science and Technology. Elsevier Science Ltd., New York, NY.nSchneider, M. H., K. I. Brebner, and I. D. Hartley. 1991 Swelling of a cell lumen filled and a cell-wall bulked wood polymer composite in water. Wood Fiber Sci.23(2):165-172.n
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