Research Progress of Soybean Protein Adhesive: A Review

Traditional formaldehyde-based adhesives rely excessively on petrochemical resources, release toxic gases, and pollute the environment. Plant-derived soybean protein adhesives are eco-friendly materials that have the potential to replace the formaldehyde-based adhesives used to fabricate wood-based panels. However, the poor water resistance, high brittleness, and poor mildew resistance of soybean protein adhesives limit their industrial applications. This article reviews recent research progress in the modification of soybean protein adhesives for improving the bonding performance of adhesives used for wood-based panel fabrication. Modification methods were summarized in terms of water resistance, solid content, and mildew resistance. The modification mechanisms and remaining problems were also discussed. Finally, the current industrial applications and the future research direction of soybean protein adhesives are discussed.