Relations of density, polyethylene glycol treatment and moisture content with stiffness properties of Vasa oak samples

Author

Alexey Vorobyev

 / Gunnar Almkvist

 / Nico P. van Dijk

 / E. Kristofer Gamstedt

Published Online: 2017-02-16 | DOI: https://doi.org/10.1515/hf-2016-0202

Abstract

Treatment with polyethylene glycol (PEG) is the preferred method for the conservation of waterlogged archaeological wooden objects. However, PEG impregnation leads to softening and increased hygroscopicity of the material. The present study compiles experimental results concerning the full elastic properties of PEG impregnated archaeological wood from the Vasa ship in relation to its basic density, PEG content (PEGC) and moisture content (MC). The results show a correlation between a more porous microstructure and high PEGC, and consequently, higher MC. The PEG and moisture contribute to the mass of the wooden object as well as to the softening of the material, which are undesired properties in a larger load-carrying wooden structure. A compromise between the improved dimensional stability and degradation of mechanical properties should therefore be considered in the conservation of wooden objects treated with PEG.

Keywords: archaeological wood; basic density; computed tomography (CT); elastic constants; moisture content (MC); PEG impregnation; Quercus robur; Vasa ship

References

• Almkvist, G., Persson, I. (2007) Degradation of polyethylene glycol and hemicellulose in the Vasa. Holzforschung 62:64–70.Google Scholar
• Almkvist, G., Persson, I. (2008) Analysis of acids and degradation products related to iron and sulfur in the Swedish warship Vasa. Holzforschung 62:694–703.Google Scholar
• Almkvist, G., Persson, I. (2011) Distribution of iron and sulfur and their speciation in relation to degradation processes in wood from the Swedish warship Vasa. N. J. Chem. 35:1491–1502.Google Scholar
• Baird, J.A., Olayo-Valles, R., Rinaldi, C., Taylor, L.S. (2010) Effect of molecular weight, temperature, and additives on the moisture sorption properties of polyethylene glycol. J. Pharm. Sci. 99:154–168.CrossrefWeb of ScienceGoogle Scholar
• Bjurhager, I., Halonen, H., Lindfors, E.L., Iversen, T., Almkvist, G., Gamstedt, E.K., Berglund, L.A. (2012) State of degradation in archeological oak from the 17th century Vasa ship: substantial strength loss correlates with reduction in (holo)cellulose molecular weight. Biomacromolecules 13:2521–2527.CrossrefGoogle Scholar
• Blanchette, R.A., Nilsson, T., Daniel, G., Abad, A.R., Rowell, R.M., Barbour, R.J. Biological degradation of wood. In: Archaeological Wood: Properties, Chemistry, and Preservation. A.C.S, Washington, DC, 1990.Google Scholar
• Cederlund, C.O., Hocker, F.M. Vasa 1 The Archaeology of a Swedish Warship of 1628. National Maritime Museum of Sweden, Stockholm, Sweden, 2006.Google Scholar
• Christensen, M., Frosch, M., Jensen, P., Schnell, U., Shashoua, Y., Nielsen, O.F. (2006) Waterlogged archaeological wood – chemical changes by conservation and degradation. J. Raman. Spectrosc. 37:1171–1178.CrossrefGoogle Scholar
• Cohen, S., Marcus, Y., Migron, Y., Dikstein, S., Shafran, A. (1993) Water sorption, binding and solubility of polyols. J. Chem. Soc. Faraday. Trans. 89:3271–3275.CrossrefGoogle Scholar
• Ding, W.D., Koubaa, A., Chaala, A., Belem, T., Krause, C. (2008) Relationship between wood porosity, wood density and methyl methacrylate impregnation rate. Wood. Mater. Sci. Eng. 3:62–70.CrossrefGoogle Scholar
• Eriksson, K.E.L., Blanchette, R.A., Ander, P. Microbial and Enzymatic Degradation of Wood and Wood Components. Springer, Berlin, 1990.Google Scholar
• Freyburger, C., Longuetaud, F., Mothe, F., Constant, T., Leban, J.M. (2009) Measuring wood density by means of X-ray computer tomography. Ann. Forest Sci. 66:804.Web of ScienceCrossrefGoogle Scholar
• Gibson, L.J., Ashby, M.F. Cellular Solids: Structure and Properties. Cambridge University Press, Cambridge, 1997.Google Scholar
• Gibson, L.J., Ashby, M.F., Harley, B.A. Cellular Materials in Nature and Medicine. Cambridge University Press, Cambridge, 2010.Google Scholar
• Gregory, D., Jensen, P., Strætkvern, K. (2012) Conservation and in situ preservation of wooden shipwrecks from marine environments. J. Cult. Herit. 13:139–148.Web of ScienceCrossrefGoogle Scholar
• Håfors, B. Conservation of the Swedish warship Vasa from 1628. Vasamuseet, Stockholm, 2001.Google Scholar
• Hassel, B.I., Berard, P., Modén, C.S., Berglund, L.A. (2009) The single cube apparatus for shear testing – Full-field strain data and finite element analysis of wood in transverse shear. Compos. Sci. Technol. 69:877–882.CrossrefWeb of ScienceGoogle Scholar
• Hedges, J.I., Rowell, R.M., Barbour, R.J. (1990) The chemistry of archaeological wood. In: Archaeological Wood: Properties, Chemistry, and Preservation. J. Am. Chem. Soc. 225:111–140.Google Scholar
• Hocker, E., Almkvist, G., Sahlstedt, M. (2012) The Vasa experience with polyethylene glycol: A conservator’s perspective. J. Cult. Herit. 13:S175–S182.CrossrefGoogle Scholar
• Hoffmann, P. (1986) On the stabilization of waterlogged oakwood with PEG. II. Designing a two-step treatment for multi-quality timbers. Stud. Conserv. 31:103–113.Google Scholar
• Hoffmann, P. (1988) On the stabilization of waterlogged oakwood with polyethylene glycol (PEG) III. Testing the oligomers. Holzforschung 42:289–294.CrossrefGoogle Scholar
• Hoffmann, P., Pätzold, J. (2001) The stabilisation of wet sediment cores by means of a polyethylene glycol/freeze-drying treatment for display and permanent storage. Geo-Marine. Lett. 21:245–252.Google Scholar
• Hoffmann, P., Bojesen-Koefoed, I., Gregory, E.D., Jensen, P. Conservation of Archaeological Ships and Boats: Personal Experiences. Archetype Publications, London, 2013.Google Scholar
• Jones, A.M., Rule, M.H., Jones, E.B.G. (1986) Conservation of the timbers of the Tudor ship Mary Rose. Dech. Monog. 6:354–362.Google Scholar
• Jover, A. (1994) The application of PEG 4000 for the preservation of palaeolithic wooden artifacts. Stud. Conserv. 39:193–198.Google Scholar
• Kellogg, R.M., Wangaard, F.F. (1969) Variation in the cell-wall density of wood. Wood. Fiber. Sci. 1:180–204.Google Scholar
• Korosi, G., Kovats, E.S. (1981) Density and surface tension of 83 organic liquids. J. Chem. Eng. Data. 26:323–332.CrossrefGoogle Scholar
• Lindfors, E.L., Lindström, M., Iversen, T. (2008). Polysaccharide degradation in waterlogged oak wood from the ancient warship Vasa. Holzforschung 62:57–63.CrossrefGoogle Scholar
• Lindgren, L.O. (1991) Medical CAT-scanning: X-ray absorption coefficients, CT-numbers and their relation to wood density. Wood. Sci. Technol. 25:341–349.Google Scholar
• Lindgren, O., Davis, J., Wells, P., Shadbolt, P. (1992) Non-destructive wood density distribution measurements using computed tomography. Holz. Roh- Werk. 50:295–299.CrossrefGoogle Scholar
• Ljungdahl, J., Berglund, L.A. (2007) Transverse mechanical behaviour and moisture absorption of waterlogged archaeological wood from the Vasa ship. Holzforschung 61:279–284.Google Scholar
• Morén, R., Centerwall, B.R. (1961) Use of polyglycols in the stabilizing and preservation of wood. Meddel en Frän Lunds Univ Hist Museum. 176–196.Google Scholar
• Norbakhsh, S., Bjurhager, I., Almkvist, G. (2014) Impact of iron (II) and oxygen on degradation of oak-modeling of the Vasa wood. Holzforschung 68: 649–655.Google Scholar
• Norimoto, M. Viscoelastic Properties of Chemically Modified Wood. Chemical Modification of Lignocellulosic Materials. Marcel Dekker, New York, 1996.Google Scholar
• Norimoto, M., Gril, J., Rowell, R.M. (1992) Rheological properties of chemically modified wood: relationship between dimensional and creep stability. Wood. Fiber. Sci. 24:25–35.Google Scholar
• Obataya, E., Ono, T., Norimoto, M. (2000) Vibrational properties of wood along the grain. J. Mater. Sci. 35:2993–3001.CrossrefGoogle Scholar
• Obataya, E., Norimoto, M., Tomita, B. (2001) Mechanical relaxation processes of wood in the low-temperature range. J. Appl. Polym. Sci. 81:3338–3347.CrossrefGoogle Scholar
• Olesen, P.O. The Water Displacement Method a Fast and Accurate Method of Determining the Green Volume of Wood Samples. Forest Tree Improvement, MI, USA, 1971.Google Scholar
• Pauli, G.F., Jaki, B.U., Lankin, D.C. (2005). Quantitative 1H NMR: development and potential of a method for natural products analysis §. J. Nat. Prod. 68:133–149.Google Scholar
• Schindelin, J., Arganda-Carreras, I., Frise, E., Kaynig, V., Longair, M., Pietzsch, T., Preibisch, S., Rueden, C., Saalfeld, S., Schmid, B., Tinevez, J.Y. (2012) Fiji: an open-source platform for biological-image analysis. Nat. Methods. 9:676–682.CrossrefWeb of ScienceGoogle Scholar
• Schniewind, A.P., Rowell, R.M., Barbour, R.J. (1990) Physical and mechanical properties of archaeological wood. In: Archaeological Wood: Properties, Chemistry, and Preservation. American Chemical Society, Washington, DC. pp. 87–109.Google Scholar
• Smith, D.M. (1954) Maximum Moisture Content Method for Determining Specific Gravity of Small Wood Samples. U.S.D.A. Madison, WI, USA, 1954.Google Scholar
• Smith, I., Landis, E., Gong, M. Fracture and Fatigue in Wood. John Wiley & Sons, Chichester, 2003.Google Scholar
• Stamm, A.J. (1956) Dimensional stabilization of wood with carbowaxes. Forest. Prod. J. 6:201–204.Google Scholar
• Svedström, K., Bjurhager, I., Kallonen, A., Peura, M., Serimaa, R. (2012) Structure of oak wood from the Swedish warship Vasa revealed by X-ray scattering and microtomography. Holzforschung 66:355–363.Google Scholar
• Tsoumis, G. Science and Technology of Wood: Structure, Properties, Utilization. Van Nostrand Reinhold, New York, 1991.Google Scholar
• Vorobyev, A., Arnould, O., Laux, D., Longo, R., van Dijk, N.P., Gamstedt, E.K. (2016) Characterisation of cubic oak specimens from the Vasa ship and recent wood by means of quasi-static loading and resonance ultrasound spectroscopy (RUS). Holzforschung 70:457–465.Google Scholar
• Wagenfuhr, R. Holzatlas. 4th Edn. 688 pp. Jodrell 581:343–344. VEB Fachbuchverlag, Leipzig, 1996.Google Scholar

About the article

Received: 2016-10-31

Accepted: 2017-01-12

Published Online: 2017-02-16

Published in Print: 2017-04-01

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Citation Information: Holzforschung, ISSN (Online) 1437-434X, ISSN (Print) 0018-3830, DOI: https://doi.org/10.1515/hf-2016-0202.

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