Fraunhofer Develops Bio-Based PU Foam Using Coatings of Grade Bio-Isocyanates

Flexible polyurethane foam that is over 90% bio-based has been developed by researchers at the Fraunhofer Institute for Structural Durability and System Reliability (LBF) in Germany.

Fraunhofer notes that the foam was produced by the OrganoFoam project using bio-based polyols and bio-based isocyanates, which are typically employed in coatings. The outcome maintained its colour for an extended period of time under ultraviolet light and was comparable to petroleum-based foams in conventional durability tests.

Fraunhofer reports that OrganoFoam is over 90% bio-based and contains only relatively small quantities of additives. Both of the primary reactants, the polyol and the isocyanate, stem from biological sources. Isocyanates are the most commonly used coating type.

The foam exhibited minimal discolouration after 700 hours of UV exposure. Typically, conventional foams turn yellow within approximately 100 hours.

Petroleum-based reference foams were comparable in terms of compression set and compression hardness. Friedrich Platt GmbH, an industrial partner, conducted processing testing. The research was funded by the German Ministry of Education and Research (BMFTR).

The significance of this is that bio-based polyurea isocyanates are being implemented in practical applications. The polyol or amine side of polyurethane and polyurea has contributed the majority of the bio-based content thus far. The isocyanate side has remained almost entirely petroleum-based.

In general, coatings-grade isocyanates are selected for their weathering capabilities, and the foam's resistance to yellowing is indicative of this.

Source: Polyurea Magazine