Studying bond formation, dewatering and rheology behavior of bio-based polymers to achieve instant tack/coating consolidation

Despite substantial research efforts, the commercial alternatives for bio-based adhesives remain scarce. There are high requirements for adhesives used for lamination of paper in food packaging, e.g., stable adhesion over shelf life, food safety, water and temperature resistance to name a few. In particular, high-speed roll-to-roll processing requires an instant tack of the adhesive to the paper substrate, to avoid sliding of paper layers on the rollers. The coating consolidation is fast (seconds) and occurs under pressure, followed by drying. High initial tack implies that the adhesive can be load-bearing during drying. There is a need to understand how physical-chemical properties of bio-based polymers influence their initial tack performance and how to modify it. This can be achieved by studying dewatering, bond formation and rheological behavior. By using conventional fossil-based adhesives as benchmark, comparisons can be made regarding chemistry and morphology. Green chemistry principles will be used to modify selected bio-based polymers (forest-, crop- or marine based) to provide new properties for formulations requiring high initial tack.