Fluorinated plastics with an expiry date
What for?
Plastics containing fluorine have become irreplaceable in many areas of everyday life due to their water-repellent and low-friction surfaces. Well-known examples are the coatings on raincoats and non-stick frying pans. However, these polymers have been criticized as “forever chemicals” that accumulate in the environment over a long period of time and can now even be detected in pets, Antarctic ice and newborn babies. A new class of fluorinated polymers with accelerated degradation, in which the fluorine can be recovered in a reusable form, is an important step towards a sustainable circular economy for plastics.
The majority of consumer goods containing fluorinated plastics, such as Teflon pans, currently end up in landfill sites: As a result, the polymers end up in the environment. These potentially toxic compounds accumulate there so that they are now detectable almost everywhere. A research team involving Christoph Fornacon-Wood and Prof. Dr. Alex J. Plajer from the Department of Macromolecular Chemistry at the University of Bayreuth has tackled this problem. The study has now been published in the journal Chemical Communications.
The researchers have succeeded in producing a new class of fluorinated polymers that contain ester bonds. Ester bonds in polymers, i.e. plastics, facilitate degradation; however, fluorinated polyesters are very rare.
Like ordinary fluorinated plastics, this new class of polymers also has non-stick properties. In addition, the new polymers can be easily degraded again via the ester bonds. “Fluorine atoms normally slow down degradation, but here it is actually accelerated by the fluorine in the material,” says Plajer. The fluorine can then be recovered from the degraded material to be reincorporated into all kinds of chemicals.
“The design of future fluorinated polymers should include an integrated option for degradation and recycling to enable a sustainable circular economy for fluorine,” says Fornacon-Wood. This is because fluorine is a limited resource and could become rare and therefore expensive in the future without recovery.
The results of the study were produced in collaboration with the Federal Institute for Materials Research and Testing (BAM) and the Free University of Berlin. The research project is part of the Collaborative Research Center 1349 “Fluorine-Specific Interactions”, which is funded by the German Research Foundation.
Source: Fluoride Recovery in Degradable Fluorinated Polyesters. Christoph Fornacon-Wood, Merlin Stühler, Alexandre Millanvois, Luca Steiner, Christiane Weimann, Dorothee Silbernagl, Heinz Sturm, Beate Paulus, Alex J. Plajer. Chemical Communications (2024)
DOI: 10.1039/d4cc02513j