Bio-based adhesives from distillers’ dried grains and soybean for wood composites:review on performance and sustainability

This review reports recent progress in the development of bio-based adhesives derived from agricultural byproducts, with emphasis on distillers’ dried grains (DDG) and soybean (SB) based systems for wood composite (WC) applications. Chemical modifications, enzymatic treatment, and hybrid formulations are examined for their ability to enhance bonding performance, moisture resistance, and durability. Performance is systematically benchmarked against conventional petroleum-based resins such as phenol–formaldehyde and polymeric methylene diphenyl diisocyanate, which currently dominate the WC industry. Drawing on standardized testing (ASTM, EN) and life-cycle assessments, the review highlights mechanical properties, water resistance, environmental impacts, and industrial readiness of bio-based adhesive categories. Finally, the review emphasizes pathways toward formaldehyde-free adhesives for sustainable WC, outline future research priorities, and positions DDG and SB derived adhesives as key enablers of the circular bioeconomy for WC manufacturing.