Rutu Patel, Mayankkumar L. Chaudhary, Ram K. Gupta
The rising demand for sustainable alternatives to petroleum-based products has accelerated research into bio-based adhesives, offering eco-friendly, biodegradable, and renewable options for industrial applications. This review provides a comprehensive overview of adhesives derived from proteins, polysaccharides, lignin, and vegetable oils (VOs), highlighting their chemical structures, modification strategies, and performance in bonding applications. Protein-based adhesives, sourced from wheat, soy, cottonseed, rapeseed, corn, milk, blood, keratin, and collagen, demonstrate strong bonding potential but often face challenges in water resistance. Polysaccharides such as cellulose and its derivatives offer versatile adhesive properties due to their abundance and modifiability, while lignin’s phenolic structure makes it a promising substitute for phenol in phenolic resins. VOs, particularly castor, soybean, linseed, palm, and jatropha oils, serve as reactive precursors for polyurethane (PU), epoxy, and alkyd adhesives, with chemical modifications enhancing their performance. Comparative analyses show that bio-based adhesives can achieve mechanical properties similar to conventional systems, though optimization is still needed. The review also discusses diverse applications, including wood composites, furniture, packaging, and automotive sectors. By emphasizing advances in synthesis strategies and environmental benefits, this work underscores the significant role of bio-based adhesives in reducing reliance on petroleum-based systems and promoting sustainable material innovation.