Surface qualification of weathered wood

Strautmann, Jean; Noël, Marion; Volkmer, Thomas (October 2013). Surface qualification of weathered wood In: Joint COST FP0904 & FP1006 International Proceeding of the Workshop on characterization of modified wood in relation to wood bonding and coating performance. Rogla, Slovenia. 16-18 Oct 2013.

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It is expected that surface delignification of wood would enhance the durability of a transparent coating. To assert suitability of outdoor natural weathering as a wood surface delignification process, wood samples of four species (Picea abies, Larix deciduas, Fagus sylvatica, Quercus robur) have been exposed to outdoor environment for one year. Regularly, their roughness, colour and water contact angle have been measured. Besides, samples of the same species have been exposed to UV irradiation at 50 W/m2 for 100 hours. In addition to the same measurements as for the naturally weathered samples, FTIR measurements have been done on those samples. Four steps during the first year of natural weathering have been clearly identified. First, contact angle, roughness and darkness increase. In a second phase they decrease. In a third phase, darkness and roughness increase again, while contact angle stay low. Finally, beech gets lighter again, while contact angle on oak increases. These four phases respectively correspond to lignin degradation, leaching of the degraded lignin, fungal colonization, and steady erosion. From these results, it can be expected that a coating applied after the second phase (1 month), or after a forced leaching of the lignin after the first phase (2 weeks), will have an enhanced durability.

Item Type:	Conference or Workshop Item (Paper)
Division/Institute:	School of Architecture, Wood and Civil Engineering School of Architecture, Wood and Civil Engineering > Institute for Materials and Wood Technology BFH Centres and strategic thematic fields > BFH Centre for Wood - Resource and Material
Name:	Strautmann, Jean; Noël, Marion and Volkmer, Thomas
Subjects:	Q Science > QC Physics Q Science > QD Chemistry T Technology > T Technology (General) T Technology > TA Engineering (General). Civil engineering (General)
Language:	English
Submitter:	Christelle Ganne-Chédeville
Date Deposited:	15 Apr 2020 12:48
Last Modified:	15 Apr 2020 12:48
Uncontrolled Keywords:	delignification lignin photodegradation weathering wood
ARBOR DOI:	10.24451/arbor.11388
URI:	https://arbor.bfh.ch/id/eprint/11388