Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS
Building on its predecessor GlyChem, the GlyPac project within the BioBall innovation area is concerned with the material utilization of plant residues from the metropolitan region in the form of functional polymers in packaging and coatings.
The apple pomace residue is used as a starting material to extract polymeric glycans (polysaccharides) using a chemical-free hot water process and to reduce these to oligomers with only 10-15 sugar building blocks using various approaches. To purify the product fraction after depolymerization, a method using ultrafiltration is being developed to separate the highly water-soluble oligomers from degradation and by-products. Through this purification and additional narrowing of the molecular weight distribution, the required size ranges of important synthetic binders (e.g. OH-rich polyesters) for printing inks and barrier coatings on packaging films are achieved in order to be able to (partially) substitute them.