Chemical modification employed as a means of probing the cell-wall micropore of pine sapwood

Hill, Callum A. S.; Papadopoulos, Antonios N.; Payne, Damian

doi:10.1007/s00226-003-0193-5

Cited by 38 publications

(27 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The correlation between weight percent gain and decay resistance was unambiguous in Corsican pine (Pinus nigra), whereas the results were less clear or even contradictory in a number of other wood species (Hill et al 2004Hill 2009). The more even distribution of acetyl groups in Corsican pine may explain the effectiveness of decay prevention (Habu et al 2006) compared with Scots pine investigated by Hill et al (2004Hill et al ( , 2009 blocking will only slow down oxidative degradation and the formation of the microcapillary pathways required for enzyme diffusion and subsequent hydrolysis ( Figure 2B). well with decay resistance (Hakkou et al 2006;Rapp et al 2008).…”

Section: Exclusion Of Moisture Through Decrease In Cell Wall Void Volumementioning

confidence: 98%

“…Thus, this theory does not provide an explanation for the initial inhibition of oxidative degradation. Hill et al (2004) suggested that a decrease in the micropore size might reduce the rate of diffusion into the wood cell wall by fungal reductants. The bulking effect caused by acetylation and DMDHEU treatment has been shown to reduce the size of micropores (Hill et al 2004;Dieste et al 2009b).…”

Section: Role Of Accessible Nutrientsmentioning

confidence: 99%

See 1 more Smart Citation

Mode of action of brown rot decay resistance in modified wood: a review

Ringman

Pilgård²,

Brischke

et al. 2013

Holzforschung

View full text Add to dashboard Cite

Chemically or physically modified wood materials have enhanced resistance to wood decay fungi. In contrast to treatments with traditional wood preservatives, where the resistance is caused mainly by the toxicity of the chemicals added, little is known about the mode of action of nontoxic wood modification methods. This study reviews established theories related to resistance in acetylated, furfurylated, dimethylol dihydroxyethyleneurea-treated, and thermally modified wood. The main conclusion is that only one theory provides a consistent explanation for the initial inhibition of brown rot degradation in modified wood, that is, moisture exclusion via the reduction of cell wall voids. Other proposed mechanisms, such as enzyme nonrecognition, micropore blocking, and reducing the number of free hydroxyl groups, may reduce the degradation rate when cell wall water uptake is no longer impeded.

show abstract

Section: Exclusion Of Moisture Through Decrease In Cell Wall Void Volumementioning

confidence: 98%

Section: Role Of Accessible Nutrientsmentioning

confidence: 99%

Mode of action of brown rot decay resistance in modified wood: a review

Ringman

Pilgård²,

Brischke

et al. 2013

Holzforschung

View full text Add to dashboard Cite

show abstract

“…The higher the initial moisture content, the more the diffusion contributes to distributing the solute within the wood (Stamm 1964). Especially cell wall penetration is a primarily diffusion-controlled process, as most cell wall pores are only accessible in a swollen state (Hill et al 2004). Many researchers, therefore, include a so-called ''diffusion phase'' into the process.…”

Section: Introductionmentioning

confidence: 99%

The influence of curing conditions on the chemical distribution in wood modified with thermosetting resins

Klüppel

Mai

2013

Wood Sci Technol

View full text Add to dashboard Cite

Scots pine (Pinus sylvestris L.) sapwood was impregnated with aqueous solutions of phenol formaldehyde and methylated melamine formaldehyde resins and subsequently cured in an oven. One set of specimens was cured in plastic bags to avoid drying (wet curing) while another set of samples was heated and water was allowed to freely evaporate (dry curing). Macroscopic resin distribution was investigated using X-ray densitometry and infrared spectroscopy (FTIR-ATR). During dry curing, the resins migrated to the wood surface resulting in a gradient. Wet curing resulted in even distribution of the resins because it was immobilized due to condensation and precipitation in the wood. Neither densitometry nor FTIR-ATR was found to be generally applicable for investigating resin distribution in modified wood. Wet curing resulted in low cell wall bulking as compared to dry curing, probably because resin precipitated before drying. Storing impregnated wood prior to curing under non-drying conditions (''diffusion phase'') also reduced cell wall penetration and bulking.

show abstract

“…Furthermore, a distinction has been made between bulk and surface modification. The former implies that the modification reagent is distributed throughout the entire cell wall, the latter that the chemical alteration is confined to the wood surface (Hill 2006).…”

Section: Introductionmentioning

confidence: 99%

“…Such processes include an impregnation step using a solution of low molecular weight that diffuses into the cell wall and subsequently polymerizes. This leads to a condition where the reagent is locked without covalently reacting with cell wall compounds (Hill 2006). Phenol-formaldehyde resins were used for impregnating OSB strands (Wan and Kim 2006) and particles (Kajita and Imamura 1991); the boards displayed strongly reduced swelling following water submersion as compared to controls.…”

Section: Introductionmentioning

confidence: 99%

Procedural influence on the properties of particleboards made from AKD modified chips

et al. 2009

View full text Add to dashboard Cite

Wood chips were treated with alkyl ketene dimer (AKD) using three different processes to impart water resistance to particleboards. In the first process, AKD was blended with UF resin. Thickness swelling and water uptake after a 24 h immersion period (20 and 69%) were lower than in the control boards (28 and 81%) but were higher than in the paraffin references (10 and 22%). In process 2, AKD and UF resin were sprayed separately on the chips resulting in a greater reduction of thickness swelling (15%) and water uptake (49%) than in process 1. Paraffin references revealed a thickness swelling and water uptake of 7 and 25%, respectively. An extension of the pressing time in processes 1 and 2 did not increase water repellence. In process 3, particleboards were made from AKD-treated chips that were cured at 130• C (24 h) prior to gluing. They showed a thickness swelling of 7% and a water uptake of 25%, whereas particleboards with paraffin exhibited levels of 8 and 29%. The thickness swelling and water uptake of boards with AKD increased when the curing time was reduced from 24 to 12 to 6 h (130 • C). Changing the curing temperature from 130 to 100• C (12 h) had no effect on board properties. The IB of boards made from pre-cured chips with AKD (24 h/130• C) was 44% lower than in controls and 35% lower than in paraffin references. This indicates that AKD impedes the adhesion.

show abstract

Chemical modification employed as a means of probing the cell-wall micropore of pine sapwood

Cited by 38 publications

References 19 publications

Mode of action of brown rot decay resistance in modified wood: a review

Mode of action of brown rot decay resistance in modified wood: a review

The influence of curing conditions on the chemical distribution in wood modified with thermosetting resins

Procedural influence on the properties of particleboards made from AKD modified chips

Contact Info

Product

Resources

About