Assessment of extracts and hydrosol from yarrow as wood preservative and its effects on physical performance

This study aimed to assess the applicability of the extract and hydrosol obtained from the yarrow (Achillea millefolium) plant, which has grown widely in places where the Mediterranean climate prevails, as an impregnation agent for wooden materials. Red pine (Pinus brutia), oriental beech (Fagus orientalis), and walnut (Juglans regia) were selected as test samples of wood. An immersion method was used for the impregnation process that was performed for different time periods, 30 min (short), 3 h, (medium), and 24 h (long). Following the impregnation process, test samples were soaked in water for 6, 24, 48, 72, and 96 h to determine some physical properties of wooden material (retention, specific gravity, shrinkage, swelling, and water uptake). The results revealed that the highest retention after yarrow extract impregnation was achieved with red pine at 10% hydrosol concentration (2.29%) in a 30 min period whereas the lowest retention was observed with walnut material at 10% hydrosol concentration (1.17%) within a 24 h period. Yarrow extract did not have a significant effect on the physical properties of impregnated wooden materials; however, it was argued that the hydrosol was effective in the dimensional stability of all test samples due to its water-repellent properties.