A team of scientists from the Fraunhofer Society and the Technical University of Munich (TUM) has produced a new polyamide family from a byproduct of cellulose production. This opens the way for a more sustainable economy with bio-based materials. Polyamides are important plastics which have been made predominantly from crude oil up until now.

Polyamides can be found in ski bindings and in cars or items of clothing.Commercially, they have been made predominantly from crude oil up until now. There are just a few “green” alternatives, such as polyamides based on castor oil.

Bio-based compounds are often significantly more expensive to produce and have therefore only been able to penetrate the market before now if they have had particular properties. A team led by Volker Sieber, professor of the Chemistry of Biogenic Raw Materials at TU Munich, has now developed a completely new polyamide family which can be produced from a byproduct of cellulose production.

The biogenic starting material, (+)-3-carene, is made up of two rings which are fused to one another. The chemists at the TUM and the Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) in Straubing have modified one of the rings in such a way that it can be opened up, yielding a long chain of molecules, a polymer.

The second ring remains intact here. In this way, instead of a linear polymer chain like in traditional polyamides, a chain which bears many small rings and other side groups emerges. This gives the polymer completely new functions.

The new polyamides have special properties which make them attractive for many applications. For example, they melt at higher temperatures than the competing crude oil derived products. In addition, the new compounds can be produced transparently as well as in a partially crystalline manner, which increases its later application possibilities using the same starting substance.