Polyamides from Waste Wood

From waste paper production to high-quality plastics can be produced. How to do this, Fraunhofer researchers have found. The operation of its environmentally friendly production process, they demonstrate from 19 to 26 October at the K show in Dusseldorf at the joint Fraunhofer stand in Hall 7, Stand SC01.

Polyamides
Various raw materials as building blocks for plastics. © Photo Fraunhofer IGB

Although oil prices in descending flight, fossil raw materials are not the way forward in the production of plastics. Especially since it has to go in times of climate change it, to release as little carbon as possible and economies more sustainable – as by increasing renewable raw materials are used. It can be produced from plant biomass due to the diversity of chemical structures and new chemicals and polymers win with outstanding features, such as the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB shows.

The Straubinger researchers are not compostable plastic bags, but stable high- performance plastics for specific applications, which can be produced environmentally friendly. At the Straubinger Institute part BioCat ITUC which conducts Professor Volker Sieber, were processes for the conversion of terpenes, ie residues of cellulose from wood, designed to biosurfactants, biobased epoxides or monomers for special impact-resistant, cold-stable polyamides (see box ‘What are terpenes? “and” Polyamide from 3-Caren “). “These high-performance polyamides of terpene-based monomers and Campherlactam Caranlactam, due to their amorphous properties high transparency,” explains project manager Dr. Harald Strittmatter. “To identify new applications, such as goggles or visors of helmets, you can.” From the biobased polyamides but can also products such as films, textiles or adhesives produced.

Enzymes and harmless substances replace chemicals

Why the Fraunhofer researchers calculated access to terpenes? “They are a renewable resource, which is a waste material of pulp production, but also in the fruit juice industry in large quantities. Thus there is no competition with food production, thereby obviating the dish-tank discussion, “explained Strittmatter.So far, these wastes are usually incinerated. This is also unsatisfactory in that the chemical structure of terpenes in its complexity is extremely interesting. “Such compounds can be produced from fossil raw materials only very expensive,” says the project manager. The particular terpene structure allows polyamides with special properties such as high transparency to manufacture. For this purpose, the terpenes have to be chemically modified. By oxidation of a so-called carbonyl group is introduced, which can be reacted in a further reaction stage to a lactam, the monomer component for polyamides. Again, the Fraunhofer method has advantages: There are fewer synthetic steps than usually required. Above all, however: “We use instead delicate chemicals, enzymes and other harmless substances,” says Strittmatter.

So far, the bio-based plastics are made even on a laboratory scale. The aim is to transfer the process to production scale. But Strittmatter and his team still pursue a far greater purpose: “We want to contribute to biologisation the economy.”