Investigations into the photodegradation of wood using microtensile testing

Turkulin, Hrvoje; Derbyshire, H.; Miller, E. R.

doi:10.1007/s00107-004-0493-y

Cited by 23 publications

(19 citation statements)

References 6 publications

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“…Even though it was not aimed to detect the exact depth of penetration of light into wood, this finding is important for the present work because it indicates that the surface layer studied here and which may be affected by visible light could be deeper than the thickness of strips used by Turkulin and coworkers (Derbyshire et al 1995(Derbyshire et al , 1996(Derbyshire et al , 1997Turkulin and Sell 2001;Turkulin et al 2004). Furthermore, pronounced colour changes even 160 lm from the surface detected in this work here are in accordance with the results of Kataoka et al (2007), but directly contradict the results by Hon and Ifju (1978) who indicate that the depth of UV light penetration does not exceed 75 lm.…”

Section: Resultsmentioning

confidence: 85%

Spectral sensitivity in the photodegradation of fir wood (Abies alba Mill.) surfaces: colour changes in natural weathering

et al. 2013

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Activation spectra of wood under natural irradiation were investigated in detail in this work. The main purpose was to study colour changes on the wood surface over time and into the depth during natural light exposure and thus to further contribute to the optimization of surface-protecting treatments. In a natural weathering test, three 80-lm-thick strips of fir wood forming the surface layer of a wood composite were exposed to light under a series of glass cut-off filters. Samples were withdrawn at intervals and tested for colour changes. Identification of the most detrimental wavebands of light causing photodegradation was performed based on recorded colour changes. With chronological development of exposure, the colour changes shifted ever deeper into the surface and further into the visible region of the spectrum. A relatively narrow waveband from 360 to 435 nm was identified in the activation spectra to be the most active band, causing the greatest proportion of recorded colour changes. However, also visible light of wavelengths up to 515 nm significantly contributed to colour changes of the surface layers.

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Section: Resultsmentioning

confidence: 85%

Spectral sensitivity in the photodegradation of fir wood (Abies alba Mill.) surfaces: colour changes in natural weathering

et al. 2013

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“…Enzymatic depolymerization, hydrolysis and oxidative reactions occur that commonly reduce the mechanical integrity of the wood. Turkulin and Sell (2002) discussed the initial increase of z-strength that they observed during photodegradation of softwoods by ultraviolet radiation. They proposed an initial 'radiation induced cross-linking' between cellulose microfibrils that was later followed by high strength losses.…”

Section: Mictrotensilementioning

confidence: 99%

“…In the former, the bigger influ- ence of plastic deformations and inter-tracheid bonding in the compound middle lamella (CML) generally causes lower strength values (Derbyshire et al 1995;Turkulin and Sell 2002).…”

Section: Mictrotensilementioning

confidence: 99%

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Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 2: Aspects of microtensile strength and chemical changes

et al. 2011

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The biotechnological application of the white rot fungus Physisporinus vitreus named ''bioincising'' is currently being investigated for permeability improvement of Norway spruce (Picea abies (L.) Karst.) wood. During short-term (-9 weeks) incubation, fungal activity induces degradation of pit membranes and a simultaneous alteration of the tracheid cell wall structure. In Part 1 of this article series, the occurrence of selective delignification and simultaneous degradation was shown by UV-microspectrophotometry (UMSP). Moreover, significant reduction of Brinell hardness was recorded after 7 and 9 weeks incubation. For a better understanding of the chemical alterations in the wood constituents and the corresponding changes of mechanical properties due to fungal activity, we applied microtensile tests on thin strips that were prepared from the surface of incubated Norway spruce wood. Indications for the occurrence of selective delignification and simultaneous degradation were evident. Determination of lignin content and carbohydrate analysis by borate anion exchange chromatography confirmed the results. The present study verifies the findings from Part 1 of this article series and from previously conducted microscopic investigations. Now, the degradation characteristics of P. vitreus are established and the bioincising process can be further optimized with higher reliability.

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“…Both effects result in a decreased ∆E-value of the irradiated sample. Besides, colour stability had to be judged cautiously when there was no presence of humidity (which is notoriously low in normal running modes of light irradiation machines), and the effect of water proved detrimental for discoloration and weathering rates; see Turkulin and Sell (2002) and Turkulin et al (2004). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 …”

Section: Glycol Modificationmentioning

confidence: 99%

Colour stabilisation of wood composites using polyethylene glycol and melamine resin

Müller

Steiner

2009

Eur. J. Wood Prod.

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Investigations into the photodegradation of wood using microtensile testing

Cited by 23 publications

References 6 publications

Spectral sensitivity in the photodegradation of fir wood (Abies alba Mill.) surfaces: colour changes in natural weathering

Spectral sensitivity in the photodegradation of fir wood (Abies alba Mill.) surfaces: colour changes in natural weathering

Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 2: Aspects of microtensile strength and chemical changes

Colour stabilisation of wood composites using polyethylene glycol and melamine resin

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