Abstract
Density of wood can be increased by filling its porous structure with polymers. Such densification processes aim to increase hardness of wood and are particularly interesting for flooring applications. This study aims to evaluate efficiency of different polymers for chemical densification based on the polymer properties. Yellow birch (Betula alleghaniensis Britt.) was chemically densified with seven monomer mixtures through acrylate monomer impregnation and electron beam in-situ polymerization. Chemical retention and polymer content of densified woods were recorded. Hardness of treated and untreated Yellow birch was measured and compared to hardness of Jatoba (Hymenaea courbaril L.). All densified woods showed higher or comparable hardness to Jatoba. Hardness of densified wood was analyzed in relation to initial density of wood and polymer content of the material using multivariable linear mixed models. Efficiency of polymers for chemical densification was evaluated through effect of polymer content on hardness with interaction coefficients. Polymer films corresponding to monomer impregnating mixtures were prepared through low energy electron beam and characterized by their glass transition temperature, micro hardness, indentation modulus and crosslinking density. Polymers showed statistically significantly different efficiencies and were separated in two main groups. Overall, polymer efficiency increased with increasing glass transition temperature of polyacrylates.
Award Identifier / Grant number: RDCPJ 500157 – 16
Award Identifier / Grant number: PCISA 514917 – 16
Acknowledgements
The authors are grateful to the industrial partners of the NSERC-Canlak Industrial Research Chair in Finishes for Interior Wood Products (CRIF) for their help and support. Many thanks to Prof. Roberto Uribe-Rendon from Kent State University (Kent, Ohio, USA) for his help with electron beam irradiation. The authors would also like to thank collaborators who provided technical support: Dr Zhao Chen for micro indentation testing, Pascale Chevalier and the Research Center for Advanced Materials (CERMA - Université Laval) for SEM imaging, as well as the whole technical team at the Renewable Materials Research Center (CRMR - Université Laval).
Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: This work is part of the research program of Natural Sciences and Engineering Research Council of Canada (NSERC) Canlak Industrial Research Chair in Finishes for Interior Wood Products (CRIF) through programs CRD (RDCPJ 500157 – 16) and PCI (PCISA 514917 – 16).
Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
References
Alberti, A., Bertini, S., Gastaldi, G., Iannaccone, N., Macciantelli, D., Torri, G., and Vismara, E. (2005). Electron beam irradiated textile cellulose fibres. Eur. Polym. J. 41: 1787–1797. https://doi.org/10.1016/j.eurpolymj.2005.02.016.Search in Google Scholar
Blomberg, Jonas, Persson, Bengt, Blomberg, Anna (2005). Effects of semi-isostatic densification of wood on the variation in strength properties with density. Wood Science and Technology 39: 339–350. https://doi.org/10.1007/s00226-005-0290-8.10.1007/s00226-005-0290-8Search in Google Scholar
Burth, D., Lechner, V., and Krebs, F. (2010). Electron beam dose rate effects. Radtech Rep. 24, 34–41.Search in Google Scholar
Cai, X. and Blanchet, P. (2010). Acrylate wood densification: effects of vacuum time and nanoparticles on chemical retention, penetration, and resin distribution. Wood Fiber Sci. 42: 318–327.Search in Google Scholar
Cai, X. and Blanchet, P. (2015). Electron-beam curing of acrylate/nanoparticle impregnated wood products. BioRes 10: 3852–3864. https://doi.org/10.15376/biores.10.3.3852-3864.Search in Google Scholar
Chao, W.Y. and Lee, A.W. (2003). Properties of southern pine wood impregnated with styrene. Holzforschung 57: 333–336. https://doi.org/10.1515/hf.2003.049.Search in Google Scholar
Coqueret, X. (2017). Radiation-induced polymerization. In: Sun, Y., Chmielewski, A. (Eds.), Applications of ionizing radiation in materials processing. Inst. Nucl. Chem. Technol, Warszawa, pp. 143–165.Search in Google Scholar
Defoort, B., Lopitaux, G., Dupillier, J.-M., Larnac, G., and Coqueret, X. (2001). Electron-beam initiated polymerization of acrylate compositions. 6. Influence of processing parameters on the curing kinetics of an epoxy acrylate blend. Macromol. Chem. Phys. 202: 3149–3156. https://doi.org/10.1002/1521-3935(20011101)202:16<3149::aid-macp3149>3.0.co;2-m.10.1002/1521-3935(20011101)202:16<3149::AID-MACP3149>3.0.CO;2-MSearch in Google Scholar
Deka, Manabendra, Gindl, Wolfgang, Wimmer, Rupert (2007). Chemical modification of Norway spruce (Picea abies (L) Karst) wood with melamine formaldehyde resin. INDIAN J. CHEM. TECHNOL 14: 134–138. https://doi.org/10.1002/pc.20265.Search in Google Scholar
Devi, R.R. and Maji, T.K. (2007). Effect of glycidyl methacrylate on the physical properties of wood–polymer composites. Polym. Compos. 28: 1–5. https://doi.org/10.1002/pc.20265.Search in Google Scholar
Devi, R.R. and Maji, T.K. (2012). Chemical modification of simul wood with styrene–acrylonitrile copolymer and organically modified nanoclay. Wood Sci. Technol. 46: 299–315. https://doi.org/10.1007/s00226-011-0406-2.Search in Google Scholar
Ding, Wei-Dan, Koubaa, Ahmed, Chaala, Abdelkader (2013). Mechanical properties of MMA-hardened hybrid poplar wood. Industrial Crops and Products 46: 304–310. https://doi.org/10.1016/j.indcrop.2013.02.004tsave.Search in Google Scholar
Ding, W.-D., Koubaa, A., Chaala, A., Belem, T., and Krause, C. (2008). Relationship between wood porosity, wood density and methyl methacrylate impregnation rate. Wood Mater. Sci. Eng. 3: 62–70. https://doi.org/10.1080/17480270802607947.Search in Google Scholar
Dinwoodie, J.M. (1975). Timber—a review of the structure-mechanical property relationship. J. Microsc. 104: 3–32. https://doi.org/10.1111/j.1365-2818.1975.tb04002.x.Search in Google Scholar
Dinwoodie, J.M. (2000). Timber: its nature and behaviour. Boca Raton: CRC Press.10.4324/9780203477878Search in Google Scholar
Dong, X., Sun, T., Liu, Y., Li, C., and Li, Y. (2015). Structure and properties of polymer-impregnated wood prepared by in-situ polymerization of reactive monomers. BioRes 10: 7854–7864. https://doi.org/10.15376/biores.10.4.7854-7864.Search in Google Scholar
Drouin, M., Blanchet, P., and Beauregard, R. (2013). Characterization of the design function in the appearance of wood products for nonresidential buildings: a conceptual framework. Int. J. Des. Objects 6: 1–16. https://doi.org/10.18848/2325-1379/cgp/v06i03/38661.Search in Google Scholar
Ellis, W.D. and O’Dell, J.L. (1999). Wood–polymer composites made with acrylic monomers, isocyanate, and maleic anhydride. J. Appl. Polym. Sci. 73: 2493–2505. https://doi.org/10.1002/(sici)1097-4628(19990919)73:12<2493::aid-app18>3.0.co;2-c.10.1002/(SICI)1097-4628(19990919)73:12<2493::AID-APP18>3.0.CO;2-CSearch in Google Scholar
Feng, G. and Ngan, A.H.W. (2002). Effects of creep and thermal drift on modulus measurement using depth-sensing indentation. J. Mater. Res. 17: 660–668. https://doi.org/10.1557/jmr.2002.0094.Search in Google Scholar
Goldstein, I. and Dreher, W. (1960). Stable furfuryl alcohol impregnating solutions. Ind. Eng. Chem. 52: 57–58. https://doi.org/10.1021/ie50601a039.Search in Google Scholar
Green, D.W., Begel, M., and Nelson, W. (2006). Janka hardness using nonstandard specimens. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory.10.2737/FPL-RN-303Search in Google Scholar
Grekin, M. and Verkasalo, E. (2013). Variations in and models for Brinell hardness of Scots pine wood from Finland and Sweden. Balt. For. 19: 128–136.Search in Google Scholar
Hamada, E. and Kaneko, R. (1992). Micro-tribological evaluations of a polymer surface by atomic force microscopes. Ultramicroscopy 42–44: 184–190. https://doi.org/10.1016/0304-3991(92)90264-k.Search in Google Scholar
Hansson, L. and Antti, A.L. (2006). The effect of drying method and temperature level on the hardness of wood. J. Mater. Process. Technol. 171: 467–470. https://doi.org/10.1016/j.jmatprotec.2005.08.007.Search in Google Scholar
Hazarika, Ankita, Deka, Biplab K, Maji, Tarun K (2015). Melamine-Formaldehyde Acrylamide and Gum Polymer Impregnated Wood Polymer Nanocomposite. Journal of Bionic Engineering 12: 304–315. https://doi.org/10.1016/S1672-6529(14)60123-2.Search in Google Scholar
Heräjärvi, H. (2004). Variation of basic density and Brinell hardness within mature Finnish Betula pendula and B. Pubescens stems. Wood Fiber Sci. 36: 216–227.Search in Google Scholar
Hill, C.A.S. (2006). Wood modification: chemical, thermal and other processes. Chichester: John Wiley & Sons, Ltd.10.1002/0470021748Search in Google Scholar
Hill, L.W. (1997). Calculation of crosslink density in short chain networks. Prog. Org. Coating 31: 235–243. https://doi.org/10.1016/s0300-9440(97)00081-7.Search in Google Scholar
Hirata, S., Ohta, M., and Honma, Y. (2001). Hardness distribution on wood surface. J. Wood Sci. 47: 1–7. https://doi.org/10.1007/bf00776637.Search in Google Scholar
Holmberg, H. (2000). Influence of grain angle on Brinell hardness of Scots pine (Pinus sylvestris L.). Holz Als Roh- Werkst 58: 1–95. https://doi.org/10.1007/s001070050392.Search in Google Scholar
Jonsson, O. (2008). Consumer perceptions and preferences on solid wood, wood-based panels, and composites: a repertory grid study. Wood Fiber Sci. 40: 663–678.Search in Google Scholar
Klüppel, A. (2017). Hardness and indentation modulus of resin-treated wood. Int. Wood Prod. J. 8: 41–44. https://doi.org/10.1080/20426445.2016.1268358.Search in Google Scholar
Kollmann, F.F.P. and Côté, W.A. (1968). Principles of wood science and technology: I solid wood. Berlin: Spinger.10.1007/978-3-642-87928-9Search in Google Scholar
Koubaa, A., Ding, W.-D., Chaala, A., and Bouafif, H. (2012). Surface properties of methyl methacrylate hardened hybrid poplar wood. J. Appl. Polym. Sci. 123: 1428–1436. https://doi.org/10.1002/app.33799.Search in Google Scholar
Krongauz, V.V. (2010). Crosslink density dependence of polymer degradation kinetics: photocrosslinked acrylates. Thermochim. Acta 503–504: 70–84. https://doi.org/10.1016/j.tca.2010.03.011.Search in Google Scholar
Lande, S., Westin, M., and Schneider, M. (2004). Properties of furfurylated wood. Scand. J. For. Res. 19: 22–30. https://doi.org/10.1080/0282758041001915.Search in Google Scholar
Lutz, J.F. (1977). Wood veneer: log selection, cutting, and drying. U.S. Department of Agriculture, Washington D.C.Search in Google Scholar
Lykidis, Charalampos, Nikolakakos, Miltiadis, Sakellariou, Evaggelos, Birbilis, Dimitrios (2016). Assessment of a modification to the Brinell method for determining solid wood hardness. Materials and Structures 49: 961–967. https://doi.org/10.1617/s11527-015-0551-4.Search in Google Scholar
Moore, G.R., Kline, D.E., and Blankenhorn, P.R. (1983). Impregnation of wood with a high viscosity epoxy resin. Wood Fiber Sci. 15: 223–234.Search in Google Scholar
Morrell, J.J. (2018). What is wrong with wood modification in the U.S.?. In: 9th European Conference on Wood Modification, 17–18 September, Arnhem, Netherlands.Search in Google Scholar
Oliver, W.C. and Pharr, G.M. (1992). An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7: 1564–1583. https://doi.org/10.1557/jmr.1992.1564.Search in Google Scholar
Ross, R.J. (2010). Wood handbook. Wood as an engineering material. Madison: USDA Forest Service, Forest Products Laboratory, General Technical Report FPL-GTR-190.10.2737/FPL-GTR-190Search in Google Scholar
Rowell, R.M. (2012). Handbook of wood chemistry and wood composites. Baton Rouge: CRC Press.10.1201/b12487Search in Google Scholar
Schissel, S.M., Lapin, S.C., and Jessop, J.L.P. (2017). Characterization and prediction of monomer-based dose rate effects in electron-beam polymerization. Radiat. Phys. Chem. 141: 41–49. https://doi.org/10.1016/j.radphyschem.2017.05.028.Search in Google Scholar
Schnabel, T., Huber, H., Grünewald, T.A., and Petutschnigg, A. (2015). Changes in mechanical and chemical wood properties by electron beam irradiation. Appl. Surf. Sci. 332: 704–709. https://doi.org/10.1016/j.apsusc.2015.01.142.Search in Google Scholar
Schneider, M.H. (1995). New cell wall and cell lumen wood polymer composites. Wood Sci. Technol. 29: 121–127. https://doi.org/10.1007/bf00229341.Search in Google Scholar
Schneider, M.H. and Witt, A.E. (2004). History of wood polymer composite commercialization. For. Prod. J. 54: 19–24.Search in Google Scholar
Starr, T., Harper, D.P., and Rials, T.G. (2014). The effects of electron beam irradiation dose on the mechanical performance of red maple (Acer rubrum). BioRes 10: 956–969. https://doi.org/10.15376/biores.10.1.956-969.Search in Google Scholar
Trey, S.M., Netrval, J., Berglund, L., and Johansson, M. (2010). Electron-beam-initiated polymerization of poly(ethylene glycol)-based wood impregnants. ACS Appl. Mater. Interfaces 2: 3352–3362. https://doi.org/10.1021/am100778q.Search in Google Scholar PubMed
Van Krevelen, D.W., and Te Nijenhuis, K. (2009). Transition temperatures. In: Krevelen, Van, and Te Nijenhuis, D.W. (Eds.), Properties of polymers. Amsterdam: K. Elsevier, pp. 129–188.10.1016/B978-0-08-054819-7.00006-6Search in Google Scholar
Wang, X., Wiedenbeck, J., and Liang, S. (2009). Acoustic tomography for decay detection in black cherry trees. Wood Fiber Sci. 41: 127–137.Search in Google Scholar
Wen, W., Becker, A.A., and Sun, W. (2017). Determination of material properties of thin films and coatings using indentation tests: a review. J. Mater. Sci. 52: 12553–12573. https://doi.org/10.1007/s10853-017-1348-3.Search in Google Scholar
Wright, J.R. and Mathias, L.J. (1993). Physical characterization of wood and wood-polymer composites: an update. J. Appl. Polym. Sci. 48: 2225–2239. https://doi.org/10.1002/app.1993.070481216.Search in Google Scholar
Wu, G., Shah, D.U., Janeček, E.-R., Burridge, H.C., Reynolds, T.P.S., Fleming, P.H., Linden, P.F., Ramage, M.H., and Scherman, O.A. (2017). Predicting the pore-filling ratio in lumen-impregnated wood. Wood Sci. Technol. 51: 1277–1290. https://doi.org/10.1007/s00226-017-0933-6.Search in Google Scholar
Xiancong, H., Meiwu, S., Guotai, Z., Hong, Z., Xiaopeng, H., and Chunlan, Z. (2008). Investigation on the electron-beam curing of vinylester resin. Radiat. Phys. Chem. 77: 643–655. https://doi.org/10.1016/j.radphyschem.2007.11.006.Search in Google Scholar
Yong Feng, L., Xiao Ying, D., Ze Guang, L., Wan Da, J., and Yi Xing, L. (2013). Effect of polymer in situ synthesized from methyl methacrylate and styrene on the morphology, thermal behavior, and durability of wood. J. Appl. Polym. Sci. 128: 13–20. https://doi.org/10.1002/app.38099.Search in Google Scholar
Zhang, Y., Wan, H., and Zhang, S.Y. (2005). Characterization of sugar maple wood-polymer composites: monomer retention and polymer retention. Holzforschung 59: 322–329. https://doi.org/10.1515/hf.2005.053.Search in Google Scholar
Zhang, Y., Zhang, S.Y., Chui, Y.H., and Wan, H. (2006). Effect of impregnation and in-situ polymerization of methacrylates on hardness of sugar maple wood. J. Appl. Polym. Sci. 99: 1674–1683. https://doi.org/10.1002/app.22534.Search in Google Scholar
© 2020 Walter de Gruyter GmbH, Berlin/Boston
