Researchers strengthen natural fiber-reinforced plastics

In Germany, natural fiber-reinforced plastics (NFRP) become more resilient when the natural fibers are encased in a special coating. This has been determined by researchers at the Fraunhofer WKI. Through the application of a resin layer and pressing to form a composite material, the NFRP exhibit improved mechanical, thermal and hygric properties and greater chemical stability. In the future, NFRP can consequently be utilized in considerably expanded areas of application, for example in the interior of vehicles.

Until now, standard thermoplastics such as polyethylene and polypropylene, which are suitable for utilization and processing at low temperatures, have been used in the production of NFRP. In collaboration with the University of Guelph in Canada, the researchers at the Fraunhofer WKI have taken technical thermoplastics made from polyamide and combined them with coated natural fibers to create novel NFRP. The NFRP exhibit enhanced mechanical properties and better chemical and thermal resistance. Through the application of a protective layer comprised of a thermosetting polymer on natural fibers, processing at temperatures of over 200 °C can be achieved. The protective layer forms a thermal barrier and prevents thermal degradation at higher processing temperatures. As a result, the resilience of the natural fibers is improved. The coated natural fibers were subsequently integrated by the scientists into chemically and thermally higher-melting polyamide by means of hot pressing.