ESTIMATION OF THE SURFACE-ENERGY AND ACID-BASE PROPERTIES OF WOOD BY MEANS OF WETTING METHOD

The important surface energy and acid-base properties for pine wood (P inus silvestris L.) have been estimated by using two contact angle tec hniques (CAT), e.g., the sessile drop method and the Wilhelmy plate me thod, respectively. According to the results, the pine wood may be cha racterized as a low surface energy polymer due to its low surface ener gy. The surface energy, gamma(s), for the pine wood was being larger i n the direction parallel to the grains as compared with the perpendicu lar direction. The Lifshitz-van der Waals (LW) energy component, gamma (s)(LW), is the major energy component for the pine wood as compared w ith the acid-base energy component, gamma(s)(AB). Furthermore, it seem s that the LW energy component, gamma(s)(LW), of pine wood is independ ent of the choice of wetting methods and of the chemical composition o f the surface. However, the surface acid-base (AB) energy component, g amma(s)(AB), for the pine wood seems to be dependent on the wetting me thods chosen. Subdivided into its contributions, the surface of pine w ood seems to be weaker in the acidic energy parameter, gamma(s)(+), an d stronger in the basic energy parameter, gamma(s)(-). Rough estimatio n of the contact angle hysteresis (CAH) and surface roughness (SR) has also been measured separately in the parallel direction and the perpe ndicular directions, respectively.