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The Wood Preservative Potentials of Valonia, Chestnut, Tara and Sulphited Oak Tannins

Tomak, E. D., Gonultas, O.
Journal of wood chemistry and technology 2018 v.38 no.3 pp. 183-197
Castanea, Coniophora puteana, Coriolus versicolor, Pinus sylvestris, Pleurotus ostreatus, Rhodonia placenta, Valonia, antifungal properties, brown-rot fungi, decay resistance, leaching, tannins, weight loss, white-rot fungi, wood, wood preservatives
This study investigated antifungal properties of four different tannins as potential environmentally friendly wood preservatives. Scots pine wood samples were impregnated with 3, 5, 10, and 15% valonia, chestnut, tara, and sulphited oak tannins, and then were exposed to brown rot fungi Coniophora puteana and Postia placenta, and white rot fungi Trametes versicolor and Pleurotus ostreatus attack to determine the best tannin type and the optimum concentration level for sufficient decay resistance. Leaching test was conducted in order to evaluate any loss in effectiveness in decay resistance due to possibility of tannin leaching. Tannins were found efficacious in suppressing brown rot fungi attacks when no leaching prior the decay test was used, however, they seemed to be ineffective against white rot fungi attacks. The lowest weight losses were obtained with valonia and chestnut tannins both for brown and white rot fungi probable related with their high ellagic tannin content.