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Thomas LH, Altaner CM, Forsyth VT, Mossou E, Kennedy CJ, Martel A, Jarvis MC. Nanostructural deformation of high-stiffness spruce wood under tension. Sci Rep 2021; 11:453. [PMID: 33432070 PMCID: PMC7801420 DOI: 10.1038/s41598-020-79676-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 12/08/2020] [Indexed: 12/17/2022] Open
Abstract
Conifer wood is an exceptionally stiff and strong material when its cellulose microfibrils are well aligned. However, it is not well understood how the polymer components cellulose, hemicelluloses and lignin co-operate to resist tensile stress in wood. From X-ray scattering, neutron scattering and spectroscopic data, collected under tension and processed by novel methods, the ordered, disordered and hemicellulose-coated cellulose components comprising each microfibril were shown to stretch together and demonstrated concerted, viscous stress relaxation facilitated by water. Different cellulose microfibrils did not all stretch to the same degree. Attempts were made to distinguish between microfibrils showing large and small elongation but these domains were shown to be similar with respect to orientation, crystalline disorder, hydration and the presence of bound xylan. These observations are consistent with a major stress transfer process between microfibrils being shear at interfaces in direct, hydrogen-bonded contact, as demonstrated by small-angle neutron scattering. If stress were transmitted between microfibrils by bridging hemicelluloses these might have been expected to show divergent stretching and relaxation behaviour, which was not observed. However lignin and hemicellulosic glucomannans may contribute to stress transfer on a larger length scale between microfibril bundles (macrofibrils).
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Affiliation(s)
- Lynne H Thomas
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Clemens M Altaner
- New Zealand School of Forestry, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - V Trevor Forsyth
- Institut Laue-Langevin, 38042, Grenoble Cedex 9, France.,Partnership for Structural Biology (PSB), 38042, Grenoble Cedex 9, France.,Faculty of Natural Sciences, Keele University, Staffordshire, ST5 5BG, UK
| | - Estelle Mossou
- Institut Laue-Langevin, 38042, Grenoble Cedex 9, France.,Partnership for Structural Biology (PSB), 38042, Grenoble Cedex 9, France.,Faculty of Natural Sciences, Keele University, Staffordshire, ST5 5BG, UK
| | - Craig J Kennedy
- School of Energy, Geoscience, Infrastructure and Society, Heriot Watt University, Edinburgh, EH14 4AS, Scotland, UK
| | - Anne Martel
- Institut Laue-Langevin, 38042, Grenoble Cedex 9, France
| | - Michael C Jarvis
- School of Chemistry, Glasgow University, Glasgow, G12 8QQ, Scotland, UK.
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