Influence of Thermal Modification on Surface Properties and Chemical Composition of Beech Wood (Fagus sylvatica L.)

Thermal modification leads to the degradation of the compounds in wood, thereby changing the chemical composition of wood, which can affect the further wood finishing. In order to determine the effect of thermal modification on wood finishing, it is important to know the properties of its surface. In this research, the influence of thermal modification on pH, surface free energy, contact angle of coating and chemical composition of beech wood was studied. The results of this study show that acidity and water contact angle on beech wood was higher and polar component of surface free energy was lower after thermal modification. Furthermore, contact angle of waterborne coating on beech wood was increased by increasing the modification temperature and the content of extractives soluble in hot water and in organic solvent was increased after thermal modification of beech wood.