Chemical modification of wood by anhydrides without solvents or catalysts

Li, Jianzhang; Furuno, T.; Katoh, Sadanobu; Uehara, Tohru

doi:10.1007/bf00776452

Cited by 53 publications

(42 citation statements)

References 3 publications

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“…A similar trend was observed by Rowell and Youngs (1981) and Li et al (2000). Additionally, the ASE of the slicewood acetylated with the microwave reaction was generally consistent with the trends observed for the liquid phase reaction, even though the values were smaller.…”

Section: Aa (Mmol) : Wood (G) Wpg (%)supporting

confidence: 85%

Comparisons and Characteristics of Slicewood Acetylation with Acetic Anhydride by Liquid Phase, Microwave, and Vapor Phase Reactions

Yang¹,

Hung²,

Wu³

et al. 2014

BioResources

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This study compared and characterized slicewood acetylation with acetic anhydride using conventional liquid phase, microwave, and vapor phase reactions. The results revealed that there were no significant differences in the flexural properties between the unmodified and acetylated slicewood, regardless of the reaction method used. Furthermore, findings concluded that the slicewood acetylated with a vapor phase reaction required less modifying agent to achieve high levels of weight percent gain (WPG). The correlations between the anti-swelling efficiency (ASE) and the WPG of the slicewood acetylated with a vapor phase reaction were higher than the conventional liquid phase and microwave reactions. The reactivity of the cellulose hydroxyl groups was sensitive to the C2 and C6 reactive sites for all three acetylation methods. However, the reactivity was more pronounced at the C2 position with a vapor phase reaction compared to the other two reactions. Nevertheless, slicewood acetylation with acetic anhydride was found to not have a significant influence on viscoelastic properties for any of the different reaction methods.

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Section: Aa (Mmol) : Wood (G) Wpg (%)supporting

confidence: 85%

Comparisons and Characteristics of Slicewood Acetylation with Acetic Anhydride by Liquid Phase, Microwave, and Vapor Phase Reactions

Yang¹,

Hung²,

Wu³

et al. 2014

BioResources

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“…ML is frequently correlated with TMT intensity and other properties such as durability, moisture behavior, and strength properties (Metsä-Kortelainen et al 2006;Brischke et al 2007;Paul et al 2007;Welzbacher et al 2007;Meyer et al 2011). By contrast, for chemical modification (CM) processes, the uptake of solid agents remaining after drying (weight percent gain [WPG]) is considered as a measure of modification intensity (Li et al 2000;Lande et al 2004;Mai and Militz 2004;Hill 2007). However, the parts of the modification agent left in the cell lumens do not contribute to cell wall modification.…”

Section: Introductionmentioning

confidence: 99%

Critical moisture conditions for fungal decay of modified wood by basidiomycetes as detected by pile tests

Meyer

Brischke

Treu³

et al. 2015

Holzforschung

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Abstract:The aim of cell wall modification is to keep wood moisture content (MC) below favorable conditions for decay organisms. However, thermally modified, furfurylated, and acetylated woods partly show higher MCs than untreated wood in outdoor exposure. The open question is to which extent decay is influenced by the presence of liquid water in cell lumens. The present paper contributes to this topic and reports on physiological threshold values for wood decay fungi with respect to modified wood. In total, 4200 specimens made from acetylated, furfurylated, and thermally modified beech wood (Fagus sylvatica L.) and Scots pine sapwood (sW) (Pinus sylvestris L.) were exposed to Coniophora puteana and Trametes versicolor. Piles consisting of 50 small specimens were incubated above malt agar in Erlenmeyer flasks for 16 weeks. In general, pile upward mass loss (ML) and MC decreased. Threshold values for fungal growth and decay (ML ≥ 2%) were determined. In summary, the minimum MC for fungal decay was slightly below fiber saturation point of the majority of the untreated and differently modified materials. Surprisingly, T. versicolor was able to degrade untreated beech wood at a minimum of 15% MC, and growth was possible at 13% MC. By contrast, untreated pine sW was not decayed by C. puteana at less than 29% MC.

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“…The majority of these property changes appear to be determined by the weight percentage gain (WPG) of the material rather than extent of hydroxyl substitution. These include dimensional stability (Stamm and Tarkow 1947;Hill and Jones 1996;Li et al 2000), decay resistance (against Coniophora puteana) (Papadopoulos and Hill 2002a;Hill et al 2005) and hygroscopicity reduction (Papadopoulos and Hill 2002b;Papadopoulos et al 2005).…”

Section: Introductionmentioning

confidence: 99%

The reduction in the fibre saturation point of wood due to chemical modification using anhydride reagents: A reappraisal

Hill

2008

HFSG

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The data from a previous study of the moisture adsorption of Corsican pine modified with linear chain carboxylic acid anhydrides (acetic, propionic, butyric, valeric, hexanoic) has been reanalysed so that moisture content is reported as a percentage of cell wall mass only. As part of this work, the change in fibre saturation point (FSP, determined from fits of the Hailwood-Horrobin model) of the modified wood has been determined as a function of weight percentage gain (WPG). The change in FSP is not determined by the extent of hydroxyl substitution of the cell wall, but is related to WPG only (as reported previously). This is also true for the relationship between monolayer water, polylayer water, molecular weight per sorption site at saturation and WPG. However, there is no simple linear relationship between calculated FSP and WPG. When the FSP was determined by solute exclusion methods, the reduction thereof could be simply explained as due to bulking of the cell wall by the bonded acyl substituents. This is not the case when the FSP is determined from adsorption isotherms. This result is interpreted as an ambiguity of determination of FSP from projections of sorption isotherms. Differences in FSP determined by the two methods (sorption versus solute exclusion) are considered to be due to incomplete wetting of the lignocellulosic material when absorbing moisture from the initial dry state.

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Chemical modification of wood by anhydrides without solvents or catalysts

Cited by 53 publications

References 3 publications

Comparisons and Characteristics of Slicewood Acetylation with Acetic Anhydride by Liquid Phase, Microwave, and Vapor Phase Reactions

Comparisons and Characteristics of Slicewood Acetylation with Acetic Anhydride by Liquid Phase, Microwave, and Vapor Phase Reactions

Critical moisture conditions for fungal decay of modified wood by basidiomycetes as detected by pile tests

The reduction in the fibre saturation point of wood due to chemical modification using anhydride reagents: A reappraisal

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