Analysis of the water vapour sorption isotherms of thermally modified acacia and sesendok

Jalaludin, Zaihan; Hill, Callum A. S.; Xie, Yanjun; Samsi, Hashim W.; Hamdan, Halimaton; Awang, Khairul; Curling, Simon

doi:10.1080/17480272.2010.503940

Cited by 60 publications

(40 citation statements)

References 22 publications

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“…The higher treatment temperature stabilized the moisture properties of the samples, which is in agreement with earlier studies (Welzbacher et al 2007, Gündüz et al 2008, Korkut and Bektas 2008, Jalaludin et al 2010, Cao et al 2012, Priadi and Hiziroglu 2013. Longer treatment time could restrain moisture absorption, but not as efficiently as increased temperature (Cao et al 2012, Priadi andHiziroglu 2013).…”

Section: Lahtela and T Kärkisupporting

confidence: 90%

Effects of impregnation and heat treatment on the physical and mechanical properties of Scots pine (Pinus sylvestris) wood

Lahtela

Kärki

2014

Wood Material Science & Engineering

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Wood modification, of which thermal modification is one of the best-known methods, offers possible improvement in wood properties without imposing undue strain on the environment. This study investigates improvement of the properties of heat-treated solid wood. Scots pine (Pinus sylvestris) was modified in two stages: impregnation with modifiers followed by heat treatment at different temperatures. The impregnation was done with water glass, melamine, silicone, and tall oil. The heat treatment was performed at the temperatures of 180°C and 212°C for three hours. The modified samples were analyzed using performance indicators and scanning electron microscope micrographs. The mechanical and physical properties were determined with water absorption, swelling, bending strength, and impact strength tests. All the modifiers penetrated better into sapwood than hardwood; however, there were significant differences in the impregnation behavior of the modifiers. As regards the effect of heat treatment, generally the moisture properties were improved and mechanical strengths impaired with increasing treatment temperature. In contrast to previous studies, the bending strength increased after melamine impregnation and mild heat treatment. It is concluded that the properties of impregnated wood can be enhanced by moderate heat treatment.

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Section: Lahtela and T Kärkisupporting

confidence: 90%

Effects of impregnation and heat treatment on the physical and mechanical properties of Scots pine (Pinus sylvestris) wood

Lahtela

Kärki

2014

Wood Material Science & Engineering

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“…In literature, desorption is most often initiated from 95% RH and a peak in absolute hysteresis is observed around 75% RH (Cordin et al 2017;Hill et al 2009Hill et al , 2012bHimmel and Mai 2015;Hosseinpourpia et al 2016;Jalaludin et al 2010;Kymäläinen et al 2015;Okubayashi et al 2005a, b;Popescu et al 2014;Popescu and Hill 2013;Shi and Avramidis 2017;Simón et al 2017;Vahtikari et al 2017;Xie et al 2011) in accordance with the present study. This is also clear from Fig.…”

Section: Sorption Hysteresissupporting

confidence: 80%

“…In recent years, when the use of automated sorption balances has become more widespread, the high RH from which desorption is initiated is typically between 90 and 96% (Ceylan et al 2014(Ceylan et al , 2012Cordin et al 2017;Hill et al 2009Hill et al , 2012bHimmel and Mai 2015;Hosseinpourpia et al 2016;Jalaludin et al 2010;Kymäläinen et al 2015;Okubayashi et al 2005a, b;Popescu et al 2014;Popescu and Hill 2013;Shi and Avramidis 2017;Simón et al 2017;Xie et al 2011). However, using this measurement procedure, it is not hysteresis between desorption and absorption isotherms that is evaluated, but hysteresis between a scanning isotherm and the absorption isotherm.…”

Section: Introductionmentioning

confidence: 99%

Scanning or desorption isotherms? Characterising sorption hysteresis of wood

Fredriksson

Thybring

2018

Cellulose

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Sorption isotherms describe the relation between the equilibrium moisture content of a material and the ambient relative humidity. Most materials exhibits sorption hysteresis, that is, desorption give higher equilibrium moisture contents than absorption at equal ambient climate conditions. Sorption hysteresis is commonly evaluated by determination of an absorption isotherm followed by desorption starting from the highest relative humidity used in the absorption measurement (typically 95%). The latter is often interpreted as the desorption isotherm but is in fact a scanning isotherm, i.e. an isotherm obtained from neither dry nor water-saturated state. In the present study, we investigated the difference between desorption isotherms and scanning isotherms determined by desorption from different high relative humidity levels reached by absorption and how this difference influenced the evaluation of sorption hysteresis. The measurements were performed on Norway spruce (Picea abies (L.) Karst.) using automated sorption balances. Hysteresis evaluated from desorption isotherms gave linear absolute sorption hysteresis for the studied relative humidity range (0-96%), whereas hysteresis evaluated from scanning isotherms gave non-linear curves with a peak between 50 and 80% relative humidity. The position of this peak depended on the relative humidity from which desorption was initiated. Consequently, understanding and evaluation of sorption hysteresis might be challenging if scanning isotherms are used instead of desorption isotherms, hereby increasing the risk of misinterpreting the results.

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“…In this context, the role of cross-linking reactions in the wall matrix (e.g. between furfural and lignin) is also important (Jämsä and Viitaniemi 2001;Wikberg and Liisa 2004;Jalaludin et al 2010). The stiffer wood matrix of HT wood is less accessible to decay fungi due to lower nano-pore sizes and a low EMC (Jalaludin et al 2010).…”

Section: Introductionmentioning

confidence: 99%

“…between furfural and lignin) is also important (Jämsä and Viitaniemi 2001;Wikberg and Liisa 2004;Jalaludin et al 2010). The stiffer wood matrix of HT wood is less accessible to decay fungi due to lower nano-pore sizes and a low EMC (Jalaludin et al 2010). Chemical modification such as acetylation, treatment with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU), or modification with phenol-formaldehyde (PF) resins (Xie et al 2015;Mai 2015, 2016), also enhances the resistance of wood to be decayed by the FR.…”

Section: Introductionmentioning

confidence: 99%

Mode of action of brown rot decay resistance of thermally modified wood: resistance to Fenton’s reagent

Hosseinpourpia

Mai

2015

Holzforschung

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Abstract:The resistance of heat treated (HT) wood to brown rot fungi has been investigated, while the role of the Fenton reaction (FR) in the initial phase of degradation was in focus. Micro-veneers made of Scots pine, were HT with various intensities and their mass losses (ML HT ) were determined before soaking with a solution of Fenton's reagent containing Fe ions and hydrogen peroxide. The mass loss of the veneers treated that way (ML FT ), their tensile strength loss (TSL FT ) and the H 2 O 2 decomposition were observed. The ML FT , TSL FT , and H 2 O 2 loss decreased with increasing ML HT of the veneers. Soaking of the veneers in acetate buffer containing only Fe without H 2 O 2 revealed that the heat treatment (HT) strongly reduces the Fe uptake by the cell walls. FTIR spectroscopy indicated oxidation of the unmodified control veneers but did not reveal predominant decay of cell wall components; the HT veneers were not changed at all due to FR. It was concluded that the reason for the enhanced resistance of HT wood to FR is attributable to hindered diffusion of Fe ions into the wood cell wall.

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Analysis of the water vapour sorption isotherms of thermally modified acacia and sesendok

Cited by 60 publications

References 22 publications

Effects of impregnation and heat treatment on the physical and mechanical properties of Scots pine (Pinus sylvestris) wood

Effects of impregnation and heat treatment on the physical and mechanical properties of Scots pine (Pinus sylvestris) wood

Scanning or desorption isotherms? Characterising sorption hysteresis of wood

Mode of action of brown rot decay resistance of thermally modified wood: resistance to Fenton’s reagent

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