Effects of impregnation of simple phenolic and natural polycyclic compounds on physical properties of wood

The impregnation of various simple phenolic and natural polycyclic compound s into wood was investigated from the viewpoints of vibrational property an d dimensional stabilizing effect. When simple phenolic compounds were impre gnated, the loss tangent (tan delta) in the longitudinal direction increase d linearly with increasing weight gain. Meanwhile, among the natural polycy clic compounds hematoxylin decreased the tan delta drastically by impregnat ion. It was suggested that the five hydroxyl groups and the pyran ring oxyg en in the hematoxylin molecule contribute to formation of the crosslinkage- type hydrogen bonds between wood components. The rigidity of hematoxylin mo lecules may also be important. By impregnation of about 10% catechol, resor cinol, and saligenin, a 40% level of antiswelling efficiency (ASE) was atta ined, although a significant dimensional stabilizing effect was not observe d after impregnation of natural polycyclic compounds.