Enzymatic recycling of thermoset polymers and their reutilisation

In recent years, polymers have become increasingly important, especially with regard to their degradation and recycling. Due to their special structure, these macromolecules cannot simply be processed using conventional recycling methods. This is where our EnPoWert project comes in: our aim is to develop an innovative enzymatic method for the degradation of these polymers. To achieve this, we are focussing on the development and systematic investigation of new enzymes that can efficiently break down different substances and groups of substances.

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Replacement of chemical-intensive solvolysis with enzymatic degradation and design-to-recycle

Technical challenges:

  • Current processes focus on thermal processing
  • Search for optimised nuclear economy
  • Need for environmentally compatible and health-friendly chemicals
  • Goal of an energy-efficient solution


Scientific-technical solutions:

  • Integration of design-to-recycle principles
  • Targeted implementation of ester and disulphide bonds as targets for enzymatic degradation
  • Use of commercially available enzymes for optimised results
  • Developed concepts for the optimal utilisation of recycling products
  • Recycling of polymers has become an indispensable part of modern society. For thermoplastic polymers that fulfil less stringent requirements, (re)melting is often used as a recycling method. This can lead to problems such as grade purity and thermal degradation due to repeated re-melting. On the other hand, cross-linked polymers, known as thermosets, are resistant to the usual recycling methods due to their network structure.

    Fraunhofer IAP has already demonstrated chemical degradation using solvolysis agents in several projects. However, this method has its own challenges: The use of chemicals can be energy-intensive and is often not optimal for the environment and health. In addition, removing the excess chemicals can require an additional, energy-intensive step.

    The core of our project is the transition from chemical-intensive to enzymatic degradation processes. The IAP has expertise in the field of enzyme development for polymer degradation. In collaboration with the IZI-BB, we aim to identify specialised enzymes that are optimised for the degradation of specific polymer types. The main aim is to investigate the degradation of two types of network polymers using these enzymes. These studies will provide us with valuable insights into the properties of the degradation products, such as their molecular weight distribution and functionality. The project aims to further develop thermoset polyesters in such a way that they can be efficiently degraded enzymatically. Finally, we will develop an experimentally validated concept for the utilisation of the degradation products in new polymers.

  • Funding

    This project is funded as part of the Fraunhofer-Gesellschaft's internal programmes.