A natural flavonoid treatment of wood: artificial weathering and decay resistance

Abstract

In this study, a natural flavonoid, chrysin, was used as a wood impregnation agent and evaluated in terms of artificial weathering and decay resistance of wood. For this purpose, Scots pine samples were impregnated with chrysin after tosylation pre-treatment and, then, exposed to artificial weathering for 672 h. Color, surface roughness, contact angle and macroscopic changes were recorded during the test period. Furthermore, surface chemical components and morphological changes were evaluated with ATR-FTIR and SEM, respectively. Decay resistance of samples was assessed using a brown-rot fungus (Coniophora puteana) and a white-rot fungus (Coriolus versicolor) for both leached and un-leached samples. In the results, chrysin impregnation was found efficacious in preventing C. puteana attack. However, a proper protection was not ensured against C. versicolor attack. Tosylation was effective in resisting decay by both fungi, but it was not effective in decreasing weathering degradation on the wood surface as chrysin impregnation did. Chrysin decreased color changes and surface roughness. In addition, surface hydrophobicity increased, and lignin degradation decreased with chrysin impregnation. Cracks on treated samples seemed to be an important disadvantage after exposure to weathering agents. Results of chrysin impregnation gave some promising results to improve service life of non/low-durable wood species in outdoor use.