The effect of lignin composition on the viscoelastic properties of wood.

Olsson, Anne-Mari; Salmén, Lennart

doi:10.3183/npprj-1997-12-03-p140-144

Cited by 121 publications

(92 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The T g of the in-situ lignin in the EW untr , S untr under EG-saturated condition was around 91°C at a frequency of 1 Hz, similar to the reported T g for spruce (Olsson and Salmén 1997). For the CS treated EW, S 180,50 , the T g decreased to 76°C, which is ca 17% lower than that for S untr .…”

Section: Resultsmentioning

confidence: 71%

See 1 more Smart Citation

Effects of thermo-hygro-mechanical (THM) treatment on the viscoelasticity of in-situ lignin

et al. 2017

Self Cite

View full text Add to dashboard Cite

For producing wood products without fractures based on thermo-hygro-mechanical (THM) treatments, it is essential to understand how steaming and compression change the wood softening and cell wall components. In this paper, the effects of compression combined with steam treatment (CS) on the viscoelasticity of the in-situ lignin of Chinese fir has been investigated through dynamic mechanical analysis (DMA) under fully saturated conditions. Several variations were studied, such as the softening temperature (T g ) and apparent activation energy (ΔH a ) of the softening process in response to CS treatment conditions (such as steam temperature and compression ratio) under separate consideration of earlywood (EW) and latewood (LW). No difference between EW and LW with respect to the viscoelasticity was noted. T g and ΔH a of the lignin softening were nearly unaffected by the compression ratio, but were highly influenced by the steam temperature. The T g decreased significantly with CS treatments at or above 160 o C, but showed no appreciable change, compared to the native wood, at the lower steaming temperature of 140 o C. ΔH a increased at higher steam temperatures, while ΔH a showed a decreasing tendency with decreasing T g . This indicates that lignin undergoes a simultaneous depolymerization as well as a condensation during CS treatment.

show abstract

Section: Resultsmentioning

confidence: 71%

“…The higher T g was assumed to be related to the increased possibility of cross-linking with increasing S/G ratio (Olsson and Salmén 1997). The fact that CS treatment leads to a decrease in T g accompanied by an increasing ΔH a may be interpreted in terms of competitive depolymerization and re-condensation reactions.…”

Section: Resultsmentioning

confidence: 99%

Effects of thermo-hygro-mechanical (THM) treatment on the viscoelasticity of in-situ lignin

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…The glass transition temperatures of OB, MB and IB with different moisture content are shown in Table 3 (Salmen 1984(Salmen , 1990. Olsson and Salmen (1997) (Kelley et al 1987). The results showed that the α 1 and α 2 transition temperatures of OB, MB, and IB were different.…”

Section: Storage Modulusmentioning

confidence: 91%

DYNAMIC MECHANICAL THERMAL ANALYSIS OF MOSO BAMBOO (Phyllostachys heterocycla) AT DIFFERENT MOISTURE CONTENT

Liu¹,

Jiang²,

Cai³

et al. 2012

BioResources

View full text Add to dashboard Cite

aBamboo is a type of biomass materials that has great potential as a bioenergy resource in China. The thermal-mechanical behavior of bamboo plays an important role in the formation process of pellets. To investigate the effect of moisture content (MC) on thermal-mechanical behavior of bamboo, the storage modulus and loss factor of moso bamboo was determined using dynamic mechanical thermal analysis (DMTA) from -50 to 150 o C. The experimental results showed that the general feature of bamboo thermal-mechanical properties with temperature is similar to other cellulosic materials, and they are affected by MC. A substantial decrease of storage modulus over the entire temperature range implies that bamboo underwent a glass to rubber transition. Bamboo, at lower MC, has a higher storage modulus, which decreases the mechanical strength of pellets. The loss factor exhibited two major transitions for all samples. There was an α-transition (α 1 ), attributed to glass transition of lignin, peaking in a higher temperature range. The second major relaxation (α 2 ), located in a lower temperature range, was attributed to glass transition of hemicelluloses. Activating lignin and hemicelluloses using moisture and temperature in the temperature range of glass transition can be very helpful to achieve durable particle-particle bonding.

show abstract

“…This can be explained by the low G content in the wood of this hybrid. G lignin moieties are known to increase the glass transition temperature of lignins probably because they increase the cross-linking density of lignins (Olsson and S á lmen 1997 ).…”

Section: Tmp Refi Ningsmentioning

confidence: 99%

Thermomechanical pulping of novel Brazilian Eucalyptus hybrids

Muguet¹,

Ruuttunen²,

Jääskeläinen³

et al. 2013

Holzforschung

View full text Add to dashboard Cite

Abstract:The importance of Eucalyptus wood as a sustainable resource is well established. Mechanical pulp production is an energy-intensive process, and methods for decreasing energy demand are needed. In the present article, the structure of Eucalyptus hybrids and the produced pulps from the hybrids were assessed in terms of energy consumption, technical properties, and fiber morphology. The defibration and fiber development were investigated by traditional thermomechanical pulping in laboratory scale. There was no clear difference in the extent of defibration and fibrillation among the hybrids, with the exception of one hybrid (U2xGL1). Guaiacyl lignin contents of more than 7.2 % had a minor influence on energy consumption, and this finding is different from the results of previous studies on chemimechanical pulping processes. However, a low amount of guaiacyl lignin (6.1 % based on wood) decreased the energy demand. This assessment is of major importance concerning the energysaving defibration during thermomechanical pulping production.

show abstract

The effect of lignin composition on the viscoelastic properties of wood.

Cited by 121 publications

References 0 publications

Effects of thermo-hygro-mechanical (THM) treatment on the viscoelasticity of in-situ lignin

Effects of thermo-hygro-mechanical (THM) treatment on the viscoelasticity of in-situ lignin

DYNAMIC MECHANICAL THERMAL ANALYSIS OF MOSO BAMBOO (Phyllostachys heterocycla) AT DIFFERENT MOISTURE CONTENT

Thermomechanical pulping of novel Brazilian Eucalyptus hybrids

Contact Info

Product

Resources

About