Viscoelastic properties of wood across the grain measured under water-saturated conditions up to 135 °C: evidence of thermal degradation
| Autor: | Vincent Placet, Joëlle Passard, Patrick Perré |
|---|---|
| Přispěvatelé: | Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’Etude et de Recherche sur le Matériau Bois (LERMAB), Université Henri Poincaré - Nancy 1 (UHP)-AgroParisTech-Institut National de la Recherche Agronomique (INRA), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Technologie de Belfort-Montbeliard (UTBM), Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université Henri Poincaré - Nancy 1 (UHP) |
| Rok vydání: | 2008 |
| Předmět: |
0106 biological sciences
Materials science Softening point FOS: Physical sciences Physics - Classical Physics 01 natural sciences Viscoelasticity Degree (temperature) [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph] Fagus sylvatica 010608 biotechnology [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph] General Materials Science thermal degradation Composite material Beech viscoelasticity 040101 forestry biology Mechanical Engineering Condensation Classical Physics (physics.class-ph) Picea abies 04 agricultural and veterinary sciences Dynamic mechanical analysis biology.organism_classification Mechanics of Materials 0401 agriculture forestry and fisheries wood |
| Zdroj: | Journal of Materials Science Journal of Materials Science, Springer Verlag, 2008, 43 (9), pp.3210-3217. ⟨10.1007/s10853-008-2546-9⟩ Journal of Materials Science, Springer Verlag, 2008, 43, pp.3210-3217. ⟨10.1007/s10853-008-2546-9⟩ |
| ISSN: | 1573-4803 0022-2461 |
| Popis: | In this paper, the viscoelastic properties of wood under water-saturated conditions are investigated from 10\degree C to 135\degree C using the WAVET* apparatus. Experiments were performed via harmonic tests at two frequencies (0.1 Hz and 1 Hz) for several hours. Four species of wood were tested in the radial and tangential material directions: oak (Quercus sessiliflora), beech (Fagus sylvatica), spruce (Picea abies) and fir (Abies pectinata). When the treatment is applied for several hours, a reduction of the wood rigidity is significant from temperature values as low as 80-90\degree C, and increases rapidly with the temperature level. The storage modulus of oak wood is divided by a factor two after three hours of exposure at 135\degree C. This marked reduction in rigidity is attributed to the hydrolysis of hemicelluloses. The softening temperature of wood is also noticeably affected by hygrothermal treatment. After three short successive treatments up to 135\degree C, the softening temperature of oak shifted from 79\degree C to 103\degree C, at a frequency of 1 Hz. This reduction in mobility of wood polymers is consistent with the condensation of lignins observed by many authors at this temperature level. In the same conditions, fir exhibited a softening temperature decreasing of about 4\degree C. In any case, the internal friction clearly raises. |
| Databáze: | OpenAIRE |
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