Scientists design new type of biodegradable plastic using reclaimed plastic


The Fraunhofer Institute for Production Systems and Design Technology IPK and its partners have developed an innovative process for creating a new type of plastic made of reclaimed waste which readily degrades in less than a year. The new substance, polyhydroxybutyrate will soon serve to manufacture and break down mainly disposable products in an ecofriendly way. This innovative material can be produced on an industrial scale with the recently developed method.

Polypropylene Like New Plastic

This new process turns industrial leftovers such as waste fats that contain a lot of mineral residue into polyhydroxybutyrate (PHB). Microorganisms can metabolize these residues in special fermentation processes. They deposit the PHB in their cells to store energy. “Once the plastic has been dissolved from the cell, it is still not ready for industrial use, because the hardening process takes far too long,” says Christoph Hein, head of the Microproduction Technology department at Fraunhofer IPK. The raw material must be mixed with chemical additives downstream in post-production stages. For example, the research team adjusted the plasticizing and processing parameters to trim the recrystallization time to fit the timing of industrial processing. The resulting biopolymer’s properties resemble those of polypropylene. But unlike PP, this plastic degrades fully in six to twelve months.

The Bioeconomy International Research Initiative

The German Federal Ministry of Education and Research (BMBF) has launched the “Bioökonomie International” (Bioeconomy International) research initiative in close cooperation with Fraunhofer IPK, the Department of Bioprocess Technology of the Technical University of Berlin, regional industrial partners and international research partners from Malaysia, Columbia and the USA. These researchers are developing a method of manufacturing polymers without drawing on premium resources such as mineral, palm and rapeseed oils, the production of which is very detrimental to the environment. In this method of producing plastic, microorganisms synthesize the entire polymer in a biotechnical process. “To this end, we convert biogenic residues such as waste fats into polyesters that can be put to technical use,” says Hein. The research team opted for microorganisms, genetically modified with molecular methods, to serve as biocatalysts. With the help of chemical purification processes and an extensively optimized material, they have been able to develop a novel family of materials that satisfy the demands of technical plastics.

Greener Plastic Alternatives

The new process not only dispenses with petroleum-based synthetic components altogether; it also enables green plastic alternatives. Naturally occurring microorganisms can break down these newly developed plastics, so they need not be subjected to the special conditions that serve to degrade matter in industrial composting plants. They offer an ecofriendly alternative to making and degrading single-use products and other disposable items. The process also lends itself to producing high-quality plastic parts for certain technical applications and periods of use. The specifications for this sort of product are more demanding. They may have to exhibit specific geometric tolerances and surface qualities or be reproducible with great precision. The researchers developed highly specialized replication processes to meet these requirements. Source: Fraunhofer Institute for Production Systems and Design Technology, 6 October 2020