Covestro, leading manufacturers of high-quality polymer, has developed an innovative process for recycling polycarbonate, i.e. polychain plastics. In this process, plastics are converted back into their monomers, a precursor of plastics, so that they can be fed back into the production process as alternative raw materials.

The newly developed process makes it possible to recycle polycarbonates and reuse the recyclate for high-performance applications such as car headlights.

"As a manufacturer of plastics such as polycarbonate, we naturally have a responsibility in dealing with these important materials, including at the end of their product life. Our advantage is: we know how our products are designed and can therefore conduct targeted research into recycling solutions," says Dr. Thorsten Dreier, Covestro's Chief Technology Officer. "The chemical recycling of polycarbonate is another example with which our colleagues in development show that closed cycles are possible in the future. We need to use end-of-life plastics as a resource and reuse them as alternative raw materials to close the loop."

The return of plastics through recycling replaces primary fossil raw materials in production. Comprehensive recycling thus contributes to climate neutrality and the protection of natural resources and the environment. Mechanical recycling of polycarbonate is already an important component of Covestro's recycling strategy. The mechanical recycling process is used whenever waste streams are sufficiently pure and the recycled polycarbonate meets the requirements profile of the future application.

Chemical recycling works in a complementary way to mechanical recycling - it converts plastic building blocks back into monomers, i.e. their individual building blocks. These can be separated and serve as raw materials for future plastic. Chemical recycling can therefore make larger waste streams that are unsuitable for mechanical processes in particular accessible for recycling; it allows the production of plastics that meet the highest quality requirements. Covestro is therefore actively developing chemical recycling.

The newly developed process, which was driven by an international team, is a specific chemolysis process adapted to polycarbonate. "Pre-sorted waste streams containing a product content of more than 50 percent polycarbonate can be recycled this way. This has been successfully demonstrated with various polycarbonate-containing plastic waste streams," explains Markus Dugal, Head of Process Technology at Covestro. "With the help of this chemolysis, the cycle can be closed to a direct precursor of polycarbonate. This makes the recycling process very sustainable."