Fatty acid derived heat sealable bio-based adhesive for sustainable food packaging

Overview

This solution is a low molecular weight cross-linked fatty acid biopolymer featuring pendant amine groups that enable additional cross-linking upon contact with heat. The bio-based adhesive delivers bond strengths of 12 N/15 mm or greater on aluminum foil bonded to paperboard after heat treatment, making it suitable as a heat sealable adhesive for food packaging applications. The product addresses growing demand for sustainable packaging materials by replacing conventional petroleum-derived adhesives with a renewable, fatty acid based alternative.

The adhesive can be supplied as an 8% solid slightly gel solution in isopropanol for spray, knife, roll, or gravure coating applications. It can also be formulated as a hot melt adhesive for manufacturers preferring that application method. The chemistry leverages amine groups as epoxy curing agents that react with carboxylic acids, esters, and other reactive electrophiles to form strong covalent bonds, while hydrogen bonds and electrostatic interactions contribute synergistically to overall adhesive performance.

Technical specifications

Key features:

• Bio-based fatty acid polymer with pendant amine groups and long hydrophobic tail bearing ester bonds
• Heat-activated cross-linking mechanism that strengthens bonds upon thermal treatment
• Bond strength of 12 N/15 mm or greater on aluminum/paper substrates after heat treatment
• Soluble in isopropanol at 8% solid weight for spray, knife, roll, and gravure coating
• Can be formulated as a hot melt adhesive
• Suitable for food packaging heat seal applications

How it works:

The amine functional groups on the biopolymer backbone serve multiple bonding roles. They act as epoxy curing agents and react with carboxylic acids, esters, and other reactive electrophiles to create covalent interlocking bonds. Beyond covalent bonding, hydrogen bonding and electrostatic interactions between the polymer and substrate surfaces contribute additional adhesive strength, resulting in durable seals suitable for packaging applications.

Technology readiness level

The adhesive has been validated at the laboratory scale using commercially available aluminum foil and paperboard substrates. The next development phase involves testing with client-specific samples, scaling production to 100 kg at pilot scale, and conducting additional Instron machine testing to further confirm adhesive strength data. This validation phase is expected to take approximately six months. The technology is currently at a research-to-pilot transition stage, with proof of concept established and scale-up activities planned as the next step toward commercial readiness.