Tannin-modified soybean protein concentratefor wod adhesive

ESPOSITO, LEANDRO; CIANNAMEA, EMILIANO; SOLABARRIETA, IGNACIO; PITER, JUAN C. ; RUSECKAITE, ROXANA ; STEFANI, PABLO M

journal of applied research in technologu & engineering

Universitat politecnica de Valencia

Lugar: Valencia; Año: 2022 vol. 3 p. 1 - 7

Soybean protein concentrate (SPC) modified with condensed mimosa tannin (CT) was employed as eco-friendly and formaldehyde-free adhesives for glued-wood joints. Eucalyptus Grandi's wood boards free of knots and cracks were used as substrate. Thermogravimetric analysis (TGA) showed that tannin provided higher thermal stability to the adhesive, which allowed expanding the temperature range for hot pressing. Apparent viscosity and dynamic contact angle were measuredto evaluate the influence of tannin content on rheological behavior and the wettability process. A classic shear-thinning behavior was observed for all the adhesives. Apparent viscosity and equilibrium contact angle reached a maximum value for low CT content. This effect was attributed to associative interactions between CT and SPC. Bonding quality parameters (wood failure percentage and shear strength) of the glued-wood joints were measured according toEN 302-1:2004 standard. SPC adhesive modified with 1 % w/w CT showed the best performance in dry conditions. These adhesives were suitable for glued-wood joints in indoor environments.