Acrylate Wood Densification: Effects of Vacuum Time and Nanoparticles on Chemical Retention, Penetration, and Resin Distribution
Keywords:Nanoparticles, surface densification, density profile, chemical retention, morphology
AbstractThe feasibility of preparing a surface-densified wood product by replacing the traditional time-consuming pressurization stage with only a short vacuum time was investigated. Sugar maple and red oak wood specimens were successfully impregnated with low-viscosity resins of 1,6 hexanediol dimethacrylate and trimethylolpropane trimethacrylate, with or without silicate nanoparticles, using vacuum times of 30 s to 10 min without pressurization. Chemical retention (CR) and vertical density profiles of the treated wood specimens were measured. The CRs obtained with the short vacuum impregnation process, even with a vacuum of 30 s or 60 s, proved comparable to those achieved by the traditional process of 30-min vacuum plus 30-min pressure. A 52-63 wt% CR was found for maple impregnated with neat resin, while the formulations containing nanoparticles achieved 44-55 wt% as the vacuum time was increased 30 s to 10 min. Oak yielded lower CR values. The vertical density profiles indicated better treatability for maple than oak. Examination of the resin and resin/nanoparticle penetration into the wood by scanning electron microscopy revealed successful wood impregnation with both nanoparticles and resin.
Ayer SW, Fell D, Wan H. (2003) Hardening of solid wood: Market opportunities and review of existing technologies. Forintek Canada Corp., Québec, QC Canada. Project No. 3678. 40 pp.nBeall FC, Witt AE, Bosco LR. (1973) Hardness and hardness modulus of wood-polymer composite. For Prod J 23(1):56-60.nBeall FC, Young WJ, Witt AE. (1975) Improvement of physical properties of aspen flakeboard by polymer introduction. Wood Sci 7(3):213-218.nBrelid PL. (2002) The influence of post-treatments on acetyl content for removal of chemicals after acetylation. Holz Roh Werkst 60:92-95.nCai X, Riedl B, Zhang SY, Wan H. (2007a) Formation and properties of nanocomposites made up from solid aspen wood, melamine-urea-formaldehyde, and clay. Holzforschung 61:148-154.nCai X, Riedl B, Zhang SY, Wan H. (2007b) Effects of nanofillers on water resistance and dimensional stability of solid wood modified by melamine-urea-formaldehyde resin. Wood Fiber Sci 39(2):307-318.nCai X, Riedl B, Zhang SY, Wan H. (2008) The impact of the nature of nanofillers on the performance of wood polymer nanocomposites. Composites: Part A 39:727-737.nDale Ellis W, O'Dell JL. (1999) Wood-polymer composites made with acrylic monomers isocyanate and maleic anhydride. J Appl Polym Sci 73:2493-2505.nFuller BS, Ellis WD, Rowell RM. (1997) Hardened and fire retardant treatment of wood for flooring. US Patent 5605767, February 25; U.S. Patent 5609915, March 11; and U.S. Patent 5683820, November.nGindl W, Zargar-Yaghubi F, Wimmer R. (2003a) Impregnation of softwood cell walls with melamine-formaldehyde resin. Biores Technol 87:325-330.nGindl W, Müller U, Teischinger A. (2003b) Transverse compression strength and fracture of spruce wood modified by melamine-formaldehyde impregnation of cell walls. Wood Fiber Sci 35(2):239-246.nMahmoud AA, Eissa AMF, Omar MS, El-Sawy AA, Shaaban AF. (2000) Improvements of white pinewood properties by impregnation with thiourea-formaldehyde resin and orthophosphoric acid. J Appl Polym Sci 77: 390-397.nMeyer JA. (1965) Treatment of wood-polymer systems using catalyst-heat techniques. For Prod J 15(9): 362-364.nMeyer JA. (1981) Wood polymer materials: State of the art. Wood Sci 14(2):49-54.nMeyer JA. (1982) Industrial use of wood-polymer materials: State of the art. For Prod J 32(1):24-29.nMoore GR, Kline DE, Blankenhorn PR. (1983) Impregnation of wood with a high viscosity epoxy resin. Wood Fiber Sci 15(3):223-234.nRowell RM. (1991) Chemical modification of wood. Pages 703-756 in: DNS Hon and N, eds. Wood and cellulosic chemistry. Marcel Dekker, Inc., New York, NY.nSchneider MH. (1994) Wood polymer composites. Wood Fiber Sci 26(1):142-151.nSchneider MH. (2001) Wood-polymer composites. Pages 9764-9766 in KHJ Buschow, RC Flemings, B Ilschner, EJ Kramer, and S Mahajan, eds. The encyclopedia of materials: Science and technology. Elsevier Science Ltd, New York.nSchneider MH, Witt AE. (2004) History of wood polymer composite commercialization. For Prod J 54(4):19-24.nSiau, JF. (1984) Transport processes in wood. Springer-Verlag, New York. 245 pp.nStamm AJ. (1964) Wood and cellulose science. Ronald Press, New York. pp. 312-358.nWan H. (2004) Wood hardening technologies. Forintek Canada Corp., Québec, QC Canada. Project 3678. Pages 82-115.nWright JR, Mathias LJ. (1993a) New lightweight materials: Balsa wood-polymer composites based on ethyl α-(hydroxymethyl)acrylate. J Appl Polym Sci 48:2241-2247.nWright JR, Mathias LJ. (1993b) Physical characterization of wood and wood-polymer composites: An uptake. J Appl Polym Sci 48:2225-2239.n
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