Direct measurement of surface adhesion between thin films of nanocellulose and urea–formaldehyde resin adhesives

When applying an adhesive to wood, the chemical heterogeneity of wood cell walls makes it difficult understand contribution they make interfacial adhesion between and as is a very complex physical phenomenon. This study, for first time, directly measured surface cellulose, major component urea–formaldehyde (UF) resin adhesives. The thin, smooth nanocellulose films, such cellulose nanofibrils (CNFs), carboxymethylated (CM)–CNFs, carboxylated nanocrystals (C–CNCs), UF resins with two formaldehyde urea (F/U) molar ratios 1.0 1.6 was using approaches: (1) direct measurement force films liquid droplets resins, (2) calculation work nanocelluloses contact angle van Oss–Chaudhury–Good method. results show that total free energies, either different or are somewhat similar, indicating similarity in their properties. However, types higher than those which shows der Waals forces dominant molecular interactions. These suggest stronger when used because have more branched structure, smoother surface, energy.