Chemical analysis of wood extractives and lignin in the oak wood of the 380 year old Swedish warship Vasa
2011 (English)Conference paper (Refereed)
In order to map the source of oxalic acid in the interior wood of the Vasa ship, an analysis of wood extractives (tannins) was conducted. Samples used for analysis were PEG-impregnated dry Vasa wood, waterlogged Vasa wood and a reference material (fresh oak). The wood material was ground and extracted with an acetone/water-mixture. In the reference sample, several types of tannins were found such as the isomers castalagin/vescalagin and grandinin and their dimmers roburin A/D and roburin B/C respectively. The results have been confirmed by NMR spectroscopy and MALDI-TOF. The interior of the waterlogged Vasa wood contained small amounts of monomers, whereas the dry, PEG treated Vasa revealed no discernible amounts of hydrolysable tannins or other easily soluble compounds. Furthermore, an analysis of lignin was made by means of chemical degradation (thioacidolysis). A decrease in the amount of β-O-4 bonds in the lignin structure would imply a formation of easily oxidized free phenolics. The products were analyzed by GC-MS, which revealed no dramatic differences between the Vasa samples and the reference. The results were confirmed by CP/MAS NMR by analyzing the differences in the aromatic region (150∼160 ppm) as well as the carbonyl region (190∼200 ppm).
Place, publisher, year, edition, pages
Polymer Technologies Polymer Chemistry
IdentifiersURN: urn:nbn:se:kth:diva-82642ScopusID: 2-s2.0-84855690823OAI: oai:DiVA.org:kth-82642DiVA: diva2:498460
16th ISWFPC( International symposium on wood, fiber, and pulping chemistry) , June 8-10 , 2011, Tianjin,P.R. China
QC 201204112012-02-122012-02-122014-09-08Bibliographically approved