Macro- and micro-mechanical properties of red oak wood (Quercus rubra L.) treated with hemicellulases
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Johannes Konnerth
Abstract
Red oak wood (Quercus rubra L.) samples were submitted to an enzymatic treatment with a commercial mixture of hemicellulases aiming at the selective depolymerization and removal of the hemicelluloses. Mechanical properties of treated samples were characterized and compared with untreated samples at two hierarchical levels. At the macrolevel, tensile properties revealed to be less sensitive to degradation of the cell wall matrix compared to compression and hardness properties. Results obtained through indentation at the microlevel indicated that hardness and the so-called reduced modulus of treated wood were significantly lowered. Accordingly, hardness and reduced elastic modulus have proven to be most sensitive to modification of the cell wall matrix by reducing the content of hemicelluloses. It is proposed that transversal and shear stresses, which are mainly carried by the cell wall matrix, are additional parameters having strong effects on elastic modulus obtained by nanoindentation. Micromechanical modeling was employed to confirm the observed changes. There is consistency between the measured and the modeled properties, obtained at both the microlevel and the macrolevel of wood.
©2010 by Walter de Gruyter Berlin New York
Articles in the same Issue
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- Creep behavior of bamboo under various desorption conditions
- Predicting the longitudinal modulus of elasticity of Sitka spruce from cellulose orientation and abundance
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- Potential Brazilian wood species for bows of string instruments
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- Short Notes
- New aspects of residual lignin isolation
- Personalia
- Horst H. Nimz celebrated his 80th birthday on April 21st, 2010
- Meetings
- Meetings
Articles in the same Issue
- Original Papers
- Pre-extraction of hemicelluloses and subsequent ASA and ASAM pulping: Comparison of autohydrolysis and alkaline extraction
- Effect of drying and rewetting of wood on cellulose molecular packing
- Determination of native (wood derived) formaldehyde by the desiccator method in particleboards generated during panel production
- A computational study of pyrolysis reactions of lignin model compounds
- Energy reduction of refining by cellulases
- Macro- and micro-mechanical properties of red oak wood (Quercus rubra L.) treated with hemicellulases
- Acoustic emission measurements and lattice simulations of microfracture events in spruce
- Impact of organosilicon treatments on the wood-water relationship of solid wood
- Analysis of the water vapour sorption behaviour of Sitka spruce [Picea sitchensis (Bongard) Carr.] based on the parallel exponential kinetics model
- Effects of modification with glutaraldehyde on the mechanical properties of wood
- Effect of glutaraldehyde on water related properties of solid wood
- Creep behavior of bamboo under various desorption conditions
- Predicting the longitudinal modulus of elasticity of Sitka spruce from cellulose orientation and abundance
- Examination of the mode I critical stress intensity factor of wood obtained by single-edge-notched bending test
- Potential Brazilian wood species for bows of string instruments
- Non-destructive assessment of green density and moisture condition in plantation-grown radiata pine (Pinus radiata D. Don.) by increment core measurements
- Development of wood decay in wound-initiated discolored wood of eastern red cedar
- The effects of subthreshold loadings of tebuconazole, DDAC, and boric acid on wood decay by Postia placenta
- Short Notes
- New aspects of residual lignin isolation
- Personalia
- Horst H. Nimz celebrated his 80th birthday on April 21st, 2010
- Meetings
- Meetings
