Biobased Foams and Adhesives

Background and Objective

Due to the price development of petrochemical raw materials and the increased environmental awareness, the replacement of adhesives and insulation materials with renewable raw materials is becoming increasingly important for manufacturers and consumers. Lignin, which is obtained in large quantities as a by-product of pulp production, is a suitable starting material for this purpose. Hence, the aim of the research project is the development of reactive lignins with which polyurethane adhesives and foams can be produced. In contrast to the established procedure, harmful starting materials are avoided.

Approach

During the first step, lignin is chemically modified to obtain pre-polymers with reactive functional groups. In the second step, the lignins are converted into foams and adhesives in two different ways: On the one hand, the synthesis of pure lignin-based polyurethanes (PUR) should take place. On the other hand, the production of polyhydroxyurethanes (PHU)/isocyanate-free polyurethanes (NIPU) is being developed. Finally, these polymerization routes will be tested for the production of foams and adhesives. The properties of the intermediate and end-products are comprehensively analyzed. The biopolymer lignin thus serves as the starting material for innovative and high-quality materials.

Our Research Questions

How can Polyurethanes (PURs, NIPUs/PHUs) be synthesized from chemically modified lignins?

Are lignin-based rigid foams and adhesives suitable for high quality products?

Is it possible to replace petrochemical based polyurethanes by chemically modified lignins?