Time/temperature equivalence in the dry wood creep response
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Nanjian Sun
Abstract
Rheology of wood molecular and supramolecular organization has mostly been conducted with dynamic methods, and the application of time/temperature equivalence typically requires plasticizers to observe segmental relaxation. Dry wood rheology offers the experimental advantage of easy moisture control, but only weak secondary relaxations are observed with dynamic methods. Static methods allow for the longer relaxation times in glassy polymers, and these relaxations are strongly stimulated by lower less damaging temperatures. This study describes the application of creep mode time/temperature equivalence to dry yellow-poplar (Liriodendron tulipifera) and southern yellow pine (Pinus spp.). It was found that time/temperature equivalence was valid from 10–170°C, but only for specimens that received a prior 30-min thermal treatment (with minor desiccation) in the range of 100–170°C. The two woods exhibited clear differences in the temperature dependence of the dry wood creep relaxation, and in the sensitivity to free volume manipulation. These findings are believed to reflect polymer structural differences in hardwoods and softwoods indicating that creep mode time/temperature studies of dry wood may be useful for the analysis of xylem polymer behavior.
©2007 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Acknowledgement
- Subject index
- Contents Volume 61 (2007)
- Author index
- Species index (scientific names)
- Meetings
- Improvement of Pinus pinaster Ait elite trees selection by combining near infrared spectroscopy and genetic tools
- Direct method for the determination of phenolic hydroxyl groups in pulp
- Comparative effect of ozone, chlorine dioxide, and hydrogen peroxide on lignin: Reactions affecting pulp colour in the final bleaching stage
- Structural modification of eucalypt pulp lignin in a totally chlorine-free bleaching sequence including a laccase-mediator stage
- Analysis of wood tissues by time-of-flight secondary ion mass spectrometry
- Isolation and identification of residual chromophores from aged bleached pulp samples
- Studies on oxidative modifications of cellulose in the periodate system: Molecular weight distribution and carbonyl group profiles
- Lignin-carbohydrate network in wood and pulps: A determinant for reactivity
- Cross polarisation/magic angle spinning 13C-NMR spectroscopic studies of cellulose structural changes in hardwood dissolving pulp process
- Fungal decay of spruce and beech wood assessed by near-infrared spectroscopy in combination with uni- and multivariate data analysis
- Paper mill sludge as a component of wood adhesive formulation
- Implementation of sorption hysteresis in multi-Fickian moisture transport
- Time/temperature equivalence in the dry wood creep response
- Neural network prediction of bending strength and stiffness in western hemlock (Tsuga heterophylla Raf.)
- Bending properties of particleboard and MDF layers
- Gold as an X-ray CT scanning contrast agent: Effect on the mechanical properties of wood plastic composites
- Lignin modification in the initial phase of softwood kraft pulp delignification with polyoxometalates (POMs)
Articles in the same Issue
- Acknowledgement
- Subject index
- Contents Volume 61 (2007)
- Author index
- Species index (scientific names)
- Meetings
- Improvement of Pinus pinaster Ait elite trees selection by combining near infrared spectroscopy and genetic tools
- Direct method for the determination of phenolic hydroxyl groups in pulp
- Comparative effect of ozone, chlorine dioxide, and hydrogen peroxide on lignin: Reactions affecting pulp colour in the final bleaching stage
- Structural modification of eucalypt pulp lignin in a totally chlorine-free bleaching sequence including a laccase-mediator stage
- Analysis of wood tissues by time-of-flight secondary ion mass spectrometry
- Isolation and identification of residual chromophores from aged bleached pulp samples
- Studies on oxidative modifications of cellulose in the periodate system: Molecular weight distribution and carbonyl group profiles
- Lignin-carbohydrate network in wood and pulps: A determinant for reactivity
- Cross polarisation/magic angle spinning 13C-NMR spectroscopic studies of cellulose structural changes in hardwood dissolving pulp process
- Fungal decay of spruce and beech wood assessed by near-infrared spectroscopy in combination with uni- and multivariate data analysis
- Paper mill sludge as a component of wood adhesive formulation
- Implementation of sorption hysteresis in multi-Fickian moisture transport
- Time/temperature equivalence in the dry wood creep response
- Neural network prediction of bending strength and stiffness in western hemlock (Tsuga heterophylla Raf.)
- Bending properties of particleboard and MDF layers
- Gold as an X-ray CT scanning contrast agent: Effect on the mechanical properties of wood plastic composites
- Lignin modification in the initial phase of softwood kraft pulp delignification with polyoxometalates (POMs)
