Investigation of interphase interaction of birch wood with impregnating composition

The purpose of this work was to study the properties of interfacial interaction of the basis of a new promising impregnating composition of used motor oil with birch wood in three mutually perpendicular directions (end, radial, tangential). Samples of birch wood were chosen as objects of study. The interfacial interaction was determined by the sessile drop method by the value of the contact angle, which makes it possible to establish a significant decrease in their values relative to distilled water when using an impregnating composition based on used motor oil, apparently as a result of the interfacial interaction between the wood and the hydrophobic matrix of the impregnating composition. When water molecules wet the hydrophilic surface of wood, which occurs as a result of adsorption and capillary condensation, water dipoles are attracted to the negatively charged surface of the molecular chains of cellulose, hemicelluloses and lignin due to the presence of unsaturated hydroxyl valences on their surface. An analysis of the dynamic and static contact angles of wetting wood impregnated with used engine oil made it possible to establish a significant increase in these angles compared to the data obtained for unimpregnated wood. The contact angles increase, apparently, as a result of the interfacial interaction of the functional groups of wood and the main components of the impregnating composition, leading to the formation of a hydrophobic surface. When comparing the contact angle of wetting wood with water and used engine oil, a decrease in its value was found when wetting used engine oil in comparison with water due to more intensive diffusion of used engine oil molecules into wood and the formation of intermolecular interactions of functional groups of wood and used engine oil.