Original scientific paper

https://doi.org/10.5552/drvind.2026.0320

Effect of Wood Ash and Boron Salts on Hygroscopicity of Sawdust Composites Bonded with Wheat Protein

Sonia Correa Jurado ; Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
José Guadalupe Rutiaga Quiñones ; Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
Nancy Eloísa Rodríguez Olalde ; Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
José Juan Alvarado Flores ; Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
Faustino Ruiz Aquino ; Universidad de la Sierra de Juárez, Ixtlán de Juárez, Mexico
Javier Ramón Sotomayor Castellanos ; Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico

Abstract

Bio-based wood composites bonded with wheat protein represent a sustainable alternative to conventional formaldehyde-based panels; however, their high moisture sensitivity limits dimensional stability and functional reliability. This study comparatively evaluated the effect of incorporating equivalent low dosages (5 wt.% dry basis) of wood ash and boron salts on the hygroscopic behavior of sawdust composites manufactured under identical formulation and processing conditions. By maintaining constant raw material, adhesive system, and consolidation parameters, the experimental design enabled direct assessment of additive performance within the same lignocellulosic matrix. Hygroscopic response was characterized through short-term water immersiontests, analyzing density, hygroexpansion, and water absorption index. Relative to the unmodified control, both additives produced statistically significant improvements with large effect sizes. Wood ash increased bulk density and markedly reduced water uptake, indicating microstructural modification and partial pore blocking. Boron salts achieved the greatest reduction in hygroexpansion, suggesting chemical stabilization of cell-wall polymers. The results demonstrate that even low mineral additions can substantially modify short-term moisture response without compromising adhesive consolidation. These findings provide controlled comparative evidence supporting the use of low-cost inorganic additives to enhance the dimensional stability of sustainable wood composites intended for interior applications.

Keywords

dimensional stability; moisture sensitivity; inorganic additives; hygroexpansion; water absorption

Hrčak ID:

348433

URI

https://hrcak.srce.hr/348433

Publication date:

11.8.2026.

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