Monomers from camphor enable biobased plastics

Within the scope of the international research project “Camphor-based polymers”, the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB will, in the coming year, research sustainable production processes for biobased monomers. These are suitable as starting materials for plastics that so far have been produced on the basis of crude oil. Camphor, a terpene produced in large quantities in China from by-products of the pulp industry, can be considered as a biobased alternative to fossil raw materials.

To this day, crude oil is an essential raw material for the production of plastics. However, since resources are finite and becoming scarcer, science and industry are looking intensively for biobased alternatives. In the project “Camphor-based polymers”, the IGB branch Bio, Electro and Chemocatalysis BioCat in Straubing, Germany, has teamed up with research and industry partners in order to make residual materials from pulp production usable for the manufacture of plastics.

Castor (ricinus) oil is a biobased alternative to crude oil as a starting material for the production of polyamides; however, it has some disadvantages. On the one hand, the cultivation of the required plants is in direct competition with food production. On the other, processing is complex and several synthesis steps are required to convert castor oil into monomers.

BioCat and its project partners have envisaged as a solution the terpene camphor, which due to its chemical structure has a high potential for the production of biobased monomers for polyamides and polyesters. Moreover, in contrast to castor oil production, both the extraction and processing of camphor is unproblematic. The terpene is produced from waste materials resulting from pulp production and is therefore not only a sustainable raw material, but also readily available. In addition, only a single synthesis step is required to produce the targeted biomonomers.

As part of the “Camphor-based polymers” project, BioCat and its partners are working on an efficient biocatalytic process for the selective functionalization of the camphor into biobased monomers. “The ultimate goal of our project is the sustainable production of biobased polymers, which ranges from the use of natural terpenes from the Chinese pulp industry to the production of polymeric materials in Germany,” explains IGB scientist Dr. Michael Hofer, who heads the project at BioCat.

In order to achieve this goal and to map out the entire value-added chain, Hofer and his team are working together with scientific and industrial project partners from China and Germany. Worldwide pulp-based camphor production currently amounts to 17 000 tonnes per year and is covered almost exclusively by only five Chinese pulp manufacturers. One of these was enlisted as an industrial partner for the project “Camphor-based polymers”. The potential for global camphor production based on pulp is estimated by the project partners to be 100 000 tonnes.

The project, which was launched in January 2018, is scheduled to run until December 2020 and is coordinated by the Chair of Chemistry of Biogenic Raw Materials at the Technical University of Munich. The Federal Ministry of Education and Research is funding the project as part of the “Bioeconomy international” program.