Effect of nano-TiO2 particle size on the bonding performance and film-forming properties of starch-based wood adhesives

Abstract

The effect of nano-TiO₂ particle size on the properties of starch-based wood adhesives was studied in this work. Our findings indicate that a smaller size of nano-TiO₂ particles corresponds with a larger specific surface area and more hydroxyl sites on the particle surface that interact with latex molecules, forming a more compact network structure. Therefore, the bonding performance and water resistance of the adhesive were enhanced. In addition, rheology results showed that the adhesive behaves as a pseudoplastic fluid. Small-angle X-ray scattering and energy dispersive spectroscopy confirmed the good compatibility and dispersion of nano-TiO₂ in the adhesive films. Diffusing wave spectroscopy and scanning electron microscopy showed that smaller TiO₂ particles were more favorable for the formation of smoother and denser films. These results are of great significance for improving the structure and properties of starch-based wood adhesives and preparing high-performance environmentally friendly biobased adhesives.

Keywords: Film-forming; Nano-TiO(2); Particle size effect; Shear strength; Starch; Wood adhesive.