Sustainable Raw Materials in Hot Melt Adhesives: A Review

Hot-melt (HM) adhesives offer advantages over their contemporary water-based and solvent-based adhesives like low volatile organic compounds (VOCs), 100% solid, fast drying, setting etc. In recent years, to reduce their dependence on dwindling petroleum resources and due to the enormous use of HM adhesives in packaging areas that demand 100% recyclability, efforts have been devoted to making these formulations completely bio-based, sustainable and biodegradable. In this attempt, research and developments have been focused on using starch, modified starch, soy protein, polylactides, polyamides, lignin and vegetable oils as a partial/fully replacement to the petrochemical-based polymers. The huge amount of research going on in the field of bio-based polymers has still not reached its complete potential in the field of HM adhesives. In this review paper, HM adhesives based on sustainable raw materials namely starch, modified starch, polyamides, poly (lactic acid), soy protein and lignin are discussed.