The Impact of Nanoparticles and Moisture Content on Bonding Strength of Urea Formaldehyde Resin Adhesive

Wood and wood products have been used in different environmental conditions. Moisture content \n(MC) and relative humidity (RH) are key parameters for these conditions and bonding strength. Nanotechnology \nhas paved the way to more durable adhesives. An experimental study was conducted to examine the effects of \nvarious nanoparticles and moisture content on bonding strength of urea formaldehyde (UF) resin adhesive. In \nthis study, nanosilicon dioxide (SiO2) and titanium dioxide (TiO2) were blended with UF. Nanoparticle reinforced \nadhesives were processed at different nano fi llers concentrations (0.5 % and 1 %) and each adhesive was tested at \nthe moisture content of 0 %, 12 %, 18 % and 25 %. According to the results of bonding strength tests, contained \nnano-SiO2 adhesives showed better bonding strengths as compared to the control (pure UF) and contained nano- \nTiO2 adhesives. The highest bonding strength has been determined at 12 % wood moisture in all specimens. Increasing \nthe moisture content has decreased bonding strength of all samples including control samples. This study \nshowed that nano (SiO2 and TiO2) particles have improved the bonding strength of pure UF. Besides, the addition \nof nano-SiO2 and nano-TiO2 changed the physicochemical properties of UF adhesive by XRD test. The novelty of \nthis study was to demonstrate that nanoparticles (SiO2 and TiO2) could be benefi cial for the bonding strength of \nUF adhesive in harsh environmental conditions.