Abstract
Oak from the Swedish warship Vasa and recent oak that was aged after impregnation with iron(II) chloride has been analyzed by FT-IR spectroscopy and submitted to tensile strength testing. The aim was to investigate correlations between FT-IR bands in the fingerprint region, chemical degradation, and tensile strength in iron contaminated oak. The concentration of carboxylic functions increased and the acetyl groups in the hemicellulose fraction were decreasing as a function of degradation time. These changes are accompanied by reduced tensile strength and elevated content of oxalic acid (OA) in both Vasa wood and the impregnated recent oak samples. To evaluate the possibility to predict tensile strength from spectral data, chemometric modeling by partial least-squares (PLS) regression was applied. The strategy of repeated double cross validation (rdCV) allowed a realistic prediction of tensile strength. Overall, chemical changes and mechanical performances of iron contaminated wood are strongly correlated and thus FT-IR spectroscopy is suited to predict the strength properties of the degraded wood.
Correction note:
Correction added after online publication on March 18, 2016: The original third sentence of the Abstract was: The concentration of carboxylic functions and the acetyl groups in the hemicellulose fraction were decreasing as a function of degradation time.
Acknowledgments
Financial support from the National Maritime Museums and Swedish National Heritage Board (Grant/Award Number: ‘3.2.2-3411-2012’) is gratefully acknowledged. We thank Dr. Gulaim Seisenbaeva for technical support with the FT-IR instrument. We thank Peter Filzmoser (TU Vienna) for support in statistics. Dr. Celine Remazeilles, Dr. Veronique Rouchon and Dr. Jacky Bernard, are acknowledged for their contributions to Figure 6. We acknowledge Anders Reimann and Eva-Lisa Lindfors (Innventia AB, Sweden), for providing reference material used in this study.
References
Almkvist, G., Persson, I. (2008a) Analysis of acids and degradation products related to iron and sulfur in the Swedish warship Vasa. Holzforschung 62:694–702.10.1515/HF.2008.130Search in Google Scholar
Almkvist, G., Persson, I. (2008b) Degradation of polyethylene glycol and hemicellulose in the Vasa. Holzforschung 62:64–70.10.1515/HF.2008.009Search in 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. New J. Chem. 35:1491–1502.10.1039/c1nj20056aSearch in Google Scholar
Barnes, R.J., Dhanoa, M.S., Lister, S.J. (1989) Standard normal variate transformation and de-trending of near-infrared diffuse reflectance spectra. Appl. Spectrosc. 43:772–777.10.1366/0003702894202201Search in Google 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 13:2521–2527.10.1021/bm3007456Search in Google Scholar PubMed
Emery, J.A., Schroder, H.A. (1974) Iron-catalyzed oxidation of wood carbohydrates. Wood Sci. Technol. 8:123–137.10.1007/BF00351367Search in Google Scholar
Faix, O. (1991) Classification of lignins from different botanical origins by FT-IR spectroscopy. Holzforschung 45:21–27.10.1515/hfsg.1991.45.s1.21Search in Google Scholar
Faix, O., Böttcher, J.H. (1992) The influence of particle-size and concentration in transmission and diffuse reflectance spectroscopy of wood. Holz. Roh. Werkst. 50:221–226.10.1007/BF02650312Search in Google Scholar
Fengel, D. (1991) Possibilities and limits of FTIR spectroscopy for the characterization of cellulose. 2. Comparison of various pulps. Papier 45:97–102.Search in Google Scholar
Filzmoser, P., Liebmann, B., Varmuza, K. (2009) Repeated double cross validation. J. Chemometr. 23:160–171.10.1002/cem.1225Search in Google Scholar
Håfors, B. Conservation of the Swedish Warship Vasa from 1628. The Vasa Museum, Stockholm, 2001.Search in Google Scholar
Kabel, M.A., van den Borne, H., Vincken, J.P., Voragen, A.G.J., Schols, H.A. (2007) Structural differences of xylans affect their interaction with cellulose. Carbohyd. Polym. 69:94–105.10.1016/j.carbpol.2006.09.006Search in Google Scholar
Kacurakova, M., Wellner, N., Ebringerova, A., Hromadkova, Z., Wilson, R.H., Belton, P.S. (1999) Characterisation of xylan-type polysaccharides and associated cell wall components by FT-IR and FT-Raman spectroscopies. Food Hydrocolloid. 13:35–41.10.1016/S0268-005X(98)00067-8Search in Google Scholar
Lindfors, E.-L., Iversen, T., Lindström, M. (2008) Polysaccharide degradation in waterlogged oak wood from the ancient warship Vasa. Holzforschung 62:57–63.10.1515/HF.2008.008Search in Google Scholar
Marchessault, R.H. (1962) Applications of infrared spectroscopy to the study of wood polysaccharides. Spectrochim. Acta 18:876–876.Search in Google Scholar
Moore, A.K., Owen, N.L. (2001) Infrared spectroscopic studies of solid wood. Appl. Spectrosc. Rev. 36:65–86.10.1081/ASR-100103090Search in Google Scholar
Norbakhsh, S., Bjurhager, I., Almkvist, G. (2013) Mimicking of the strength loss in the Vasa: model experiments with iron-impregnated recent oak. Holzforschung 67:707–714.10.1515/hf-2012-0150Search in 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 68:649–655.10.1515/hf-2013-0197Search in Google Scholar
Pappas, C., Rodis, P., Tarantilis, P.A., Polissiou, M. (1999) Prediction of the pH in wood by diffuse reflectance infrared Fourier transform spectroscopy. Appl. Spectrosc. 53:805–809.10.1366/0003702991947360Search in Google Scholar
Pauli, G.F., Jaki, B.U., Lankin, D.C. (2005) Quantitative H-1 NMR: Development and potential of a method for natural products analysis. J.Nat. Prod. 68:133–149.10.1021/np0497301Search in Google Scholar PubMed
R-project. R: a language and environment for statistical computing (2014). R Development Core Team, Foundation for Statistical Computing, www.r-project.org, Vienna, Austria.Search in Google Scholar
Remazeilles, C., Quillet, V., Bernard, J. (2000) FTIR techniques applied to iron gall inked damaged paper. In: Proceedings of the 15th WCNDT, Roma, http://www.ndt.net/article/wcndt00/papers/idn323/idn323.htm.Search in Google Scholar
Remazeilles, C., Rouchon-Quillet, V., Bernard, J. (2004) Influence of gum arabic on iron gall ink corrosion part I: a laboratory samples study. Restaur. 25:220–232.10.1515/REST.2004.220Search in Google Scholar
Schwanninger, M., Rodrigues, J.C., Pereira, H., Hinterstoisser, B. (2004). Effects of short-time vibratory ball milling on the shape of FT-IR spectra of wood and cellulose. Vib. Spectrosc. 36:23–40.10.1016/j.vibspec.2004.02.003Search in Google Scholar
Varmuza, K., Filzmoser, P. Introduction to Multivariate Statistical Analysis in Chemometrics. CRC Press, Boca Raton, FL, USA, 2009.10.32614/CRAN.package.chemometricsSearch in Google Scholar
Varmuza, K., Filzmoser, P. (2014) Repeated double cross validation (rdCV) – a strategy for optimizing empirical multivariate models, and for comparing their prediction performances. In: Current Applications of Chemometrics. Ed. Khanmohammadi, M., Nova Science Publishers, Hauppauge, NY, USA. pp. 15–32.Search in Google Scholar
Varmuza, K., Filzmoser, P., Dehmer, M. (2013) Multivariate linear QSPR/QSAR models: rigorous evaluation of variable selection for PLS. Comput. Struc. Biotech. J. 5:1–10.10.5936/csbj.201302007Search in Google Scholar PubMed PubMed Central
Wojdyr, M. (2010) Fityk: a general-purpose peak fitting program. J. Appl. Crystallogr. 43:1126–1128.10.1107/S0021889810030499Search in Google Scholar
Wold, S., Sjostrom, M., Eriksson, L. (2001) PLS-regression: a basic tool of chemometrics. Chemometr. Intell. Lab. 58:109–130.10.1016/S0169-7439(01)00155-1Search in Google Scholar
Xie, Y.J., Klarhofer, L., Mai, C. (2012) Degradation of wood veneers by Fenton reagents: effects of 2,3-dihydroxybenzoic acid on mineralization of wood. Polym. Degrad. Stabil. 97:1270–1277.10.1016/j.polymdegradstab.2012.05.031Search in Google Scholar
Zhbankov, R.G. Chapter V. (1966) Oxidation products of cellulose. Salts of oxidation products of cellulose. In: Infrared Spectra of Cellulose and Its Derivatives. Consultants Bureau, New York.Search in Google Scholar
©2016 Walter de Gruyter GmbH, Berlin/Boston