Bioresistance of thermally modified<i>Populus tremuloides</i>(North American Aspen) wood against four decay fungi

Lekounougou, S.; Kocaefe, Duygu

doi:10.1179/2042645312y.0000000018

Cited by 6 publications

(4 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, the mechanical properties of wood decrease upon heating (Haygreen and Bowyer 1996, Kocaefe et al 2008, Lekounougou and Kocaefe 2013. When wood is heated to high temperature, thermal degradation and formation of furfurals monomers occur, thus, resulting in weight loss (Homan et al 2000, Waskett andSelmes 2001).…”

Section: Effect Of Thermal Modification Temperature On the Mechanicalmentioning

confidence: 97%

Effect of thermal modification temperature on the mechanical properties, dimensional stability, and biological durability of black spruce (Picea mariana)

Lekounougou

Kocaefe

2014

Wood Material Science & Engineering

View full text Add to dashboard Cite

This study was aimed at evaluating the effect of thermal modification temperature on the mechanical properties, dimensional stability, and biological durability of Picea mariana. The boards were thermally modified at different temperatures 190, 200 and 210°C. The results indicated that the thermal modification of wood caused a significant decrease in the modulus of rupture (MOR) after 190°C, while the modulus of elasticity (MOE) seemed less affected with a slight increase up to 200°C and slight decrease with further increase in temperature. The hardness of the thermally modified wood increased in the axial direction. This increase was also observed in tangential and axial directions but at a lesser extent. The final value was slightly higher in axial direction and lower in radial and tangential directions compared to those of the untreated wood. Dimensional stability improved with thermal modification in the three directions compared to the dimensional stability of unmodified wood. The fungal degradation results showed that the decay resistance of thermally modified wood against the wood-rotting fungi Trametes versicolor and Gloephyllum trabeum improved compared to that of the untreated wood. By contrast, the thermal modification of P. mariana had a limited effect on the degradation caused by the fungus Poria placenta.

show abstract

Section: Effect Of Thermal Modification Temperature On the Mechanicalmentioning

confidence: 97%

Effect of thermal modification temperature on the mechanical properties, dimensional stability, and biological durability of black spruce (Picea mariana)

Lekounougou

Kocaefe

2014

Wood Material Science & Engineering

View full text Add to dashboard Cite

show abstract

“…Beech (Fagus sylvatica) heat treated at 240 °C for 8 h was found to undergo weight loss due to T. versicolor attack of approximately 5% [40]. Enzymatic activities were detected only in the first 30 days of exposure and ceased after this period.…”

Section: Fungi Resistancementioning

confidence: 99%

“…Tannins performed efficiently against brown-rot fungi for both leached and unleached treatment levels (Figure 4a). In the case of HT T/DOT, durability improvement was approximately twice as high Beech (Fagus sylvatica) heat treated at 240 • C for 8 h was found to undergo weight loss due to T. versicolor attack of approximately 5% [40]. Enzymatic activities were detected only in the first 30…”

Section: Fungi Resistancementioning

confidence: 99%

Influence of Heat Treatment and Tannin Impregnation on Boron Depletion and Wood Durability

Lopes

Barnes

Bobadilha

2020

Forests

View full text Add to dashboard Cite

Heat treatment (HT) of a mixture of tannins and inorganic boron compounds showed effective results against wood decay organisms. Boron compounds play a critical role in the preservation of wood against wood decay organisms. The use of tannins and HT represents a relatively new environmentally friendly approach to the wood preservation industry. The aim of this study was to investigate the effect of tannin impregnation and HT on boron depletion, and termite and fungi resistance. Southern yellow pine (SYP) and yellow-poplar (YP) cube samples were used for this study. A mixture of condensed tannins from the Quebracho tree and disodium octaborate tetrahydrate (DOT) was injected into the specimens using a vacuum/pressure cycle, and the specimens were then heat-treated under N 2 atmosphere for four hours at 190 • C to investigate both the tannin's fixative ability to reduce boron leaching and the performance of the mixture against brown and white-rot fungi and termites. Tannins restricted boron leaching in 46% and 34% for SYP and YP, respectively, and also significantly increased the resistance against white-rot fungi for YP. Tannins and HT showed unpredictably good performance against termites. Tannins may be acting to denature proteins; in that case, fungal enzymes would be inhibited. This study revealed the importance of HT on a mixture of boron and tannins to decrease boron leaching and increase the durability of preservative systems.products is limited because of boron's natural solubility in water, which leads to a rapid depletion of treated wood in outdoor exposed conditions [7][8][9][10][11][12].Research has been conducted to address boron depletion. The most common strategies for reducing boron leaching are surface and envelope treatments, wood bulking, the use of water repellant, organo-boron compounds, a combination of biocides and non-biocidal agents, metallo-borates, stabilized boro-esters, protein borates, in situ polymerization and boron silicates [13][14][15][16][17][18][19].Previous research has shown the potential of boron fixation by tannin auto condensation. The authors in [20] described a mechanism in which boric acid was partly fixed to a condensed tannin network with boron mobility being maintained. The authors in [21] leached a mixture of tannins and boron for 80 h. After the leaching period, a 30% loss of boron occurred. The trend of increased leaching continued as the experiment progressed.The effectiveness of tannins toward fixing boron under high temperatures and for longer leaching periods has not yet been investigated. In addition, little research has been done regarding boron's efficacy on multiple wood species. Broadening this spectrum is relevant in order to improve durability across the widely varying range of species and characteristics of wood [22][23][24].In this study, a solution of disodium octaborate tetrahydrate (DOT) and condensed tannins were pressure and heat-treated into southern yellow pine and yellow-poplar with the aim of reducing boron leaching. In addition, performance ...

show abstract

“…The heat treatment or thermal modification has been widely studied because it promotes several advantages to the wood such as lower hygroscopicity, lower equilibrium moisture content, higher dimensional stability (Giebeler 1983), higher decay fungi resistance (Lekounougou and Kocaefe 2013) and color change (Garcia et al 2014. The heat-treated wood undergoes physical (Awoyemi andJones 2011, Bernabei andSalvatici 2016) and chemical modifications (Esteves et al 2011) but the last one is the most important in terms of impact on the properties of the material.…”

Section: Introductionmentioning

confidence: 99%

Wettability of the surface of heat-treated juvenile teak wood assessed by drop shape analyzer

Lopes

Garcia²,

Nascimento

2018

Maderas, Cienc. tecnol.

View full text Add to dashboard Cite

This study investigated the effect of the heat treatment on the wettability of the surface of juvenile teak (Tectona grandis) wood assessed by drop shape analyzer. Heartwood and sapwood samples were heat-treated at 180 and 200ºC. Contact angle measurements were done every 5 s for 120 s using a KRÜSS DSA100. Heartwood had lower wettability than sapwood. Heat-treatment decreased the surface wettability of both heartwood and sapwood, especially in the wood treated at 200ºC. Heartwood had lower wettability than sapwood, even after heat treatment.

show abstract

Bioresistance of thermally modifiedPopulus tremuloides(North American Aspen) wood against four decay fungi

Cited by 6 publications

References 26 publications

Effect of thermal modification temperature on the mechanical properties, dimensional stability, and biological durability of black spruce (Picea mariana)

Effect of thermal modification temperature on the mechanical properties, dimensional stability, and biological durability of black spruce (Picea mariana)

Influence of Heat Treatment and Tannin Impregnation on Boron Depletion and Wood Durability

Wettability of the surface of heat-treated juvenile teak wood assessed by drop shape analyzer

Contact Info

Product

Resources

About