Institute of Technical Biocatalysis
Hamburg University of Technology
Denickestr. 15; 21073 Hamburg
Office: DE15, 1514
Tel.: +40 42878 4265
Nowadays, it is impossible to imagine our life without synthetic polymers. Apart from their use for packaging, household items or electrical and electronic equipment they are also increasingly employed in the automotive and aerospace industry. In this context, epoxy-based carbon fiber reinforced polymers (CFRPs) have become an important material for lightweight applications. These composite materials consist of woven sheets of carbon fibers that are structurally reinforced by an epoxy polymer matrix. With their excellent mechanical properties, CFRPs are now capable of replacing components that were previously made of metals. In fact, composite materials already account for the majority of materials used in some aircraft models such as the Airbus A350, 52 % of which are CFRPs.
However, as for most plastic types, there are no sustainable recycling approaches available to allow the polymer matrix and carbon fibers to be reused beyond their life cycle. With an ongoing increase, the demand for carbon fibers is expected to exceed the production capacity by 24,000 t in 2022 while around 30 % of the produced fibers are assumed to accumulate as waste. Even though, approaches towards the development of recycling processes have been taken, the separation of the fibers from the polymer matrix still poses a major problem and is often the reason for a lower quality of the recycled fibers. As a consequence, sustainable technologies need to be developed that entail the potential for the recovery of high quality carbon fibers from waste CFRPs, while ideally breaking down the epoxy resin matrix into newly usable monomers.
Hence, the aim of this research project is to depolymerize the synthetic matrix independently of toxic chemicals and harsh conditions by the use of enzymes as green catalysts to recycle both the carbon fibers and epoxy resin. Since no enzyme capable of degrading epoxy-based polymers has yet been identified, an exploratory approach is being taken to screen the natural biodiversity for such catalysts. Potential candidates will be extensively characterized followed by the optimization of the reaction conditions to realize a technical implementation of a recycling process. This is accompanied by the development of comprehensive degradation analytics of the composite material to ensure an optimal monitoring of the process. These efforts are intended to contribute to the development of a circular polymer bio-economy.