Effect of selected solvents on the properties of glue, wood surface and adhesive force during bio-machining fluid development

This study explores the potential for biodegradable machining fluid for wood processing based on common ingredients: water, ethanol, hexane, glycerol, and various ionic liquids, examining its impact on glue properties, Scots pine wood surfaces, and adhesive force. A review of the literature confirms over 60% degradation of all components of the machining fluid within 28 days, except for IL2 and IL3. The research results suggest using water as the main component of the machining fluid due to its highest thermal conductivity and heat capacity values, and ethanol as an equivalent to organic solvents capable of degreasing blade surfaces while rapidly evaporating to cool the blade surfaces, ensuring low viscosity even as one of the main components. Empirical tests confirmed no impact of the studied components of the machining fluid on the solubility of glue and the mechanical properties of the glued joints. Fourier Transform Infrared Spectroscopy analysis with Principal Component Analysis indicated the most significant impact of glycerol on the chemical structure of the wood. However, results confirm the possibility of using this compound as a viscosity regulator for the bio-machining fluid, characterized by a vapor pressure more than 2000 times lower than that of SMF2, indicating the high thermal stability of this component.