Recyclable fluorine improves properties of degradable polyester plastics

The incorporation of fluorine into certain polyesters accelerates the formation of polymer chains, makes longer chains accessible and allows the properties of the material to be modified in a targeted manner. As a result, fluoropolyesters become more competitive with other types of plastics, while fluorine can be recovered during degradation.

This is the conclusion of a study carried out by the University of Bayreuth, published in the journal Modified chemistry.

Polyesters are becoming increasingly popular plastics due to their relatively simple chemical recycling potential. However, compared to other types of plastics, polyesters have significantly more limited applications, due to their thermal, mechanical and chemical properties.

Extending polymer chains or increasing their thermal stability can improve their usability. Through chemical modifications, such as the incorporation of additional molecules, the properties of polyesters can be precisely tailored. This expands the range of potential applications and improves the competitiveness of this type of plastic.

A research team led by Professor Alex J. Plajer from the University of Bayreuth, in collaboration with researchers from Berlin, recently developed a new class of fluoropolyesters that degrade more easily than conventional polyesters thanks to embedded fluorine.

In a follow-up study, they managed to further develop these fluoropolyesters, making them more competitive with other types of plastic.

“Fluorinated polyesters are particularly interesting because fluorine, as the most electronegative element, attracts electrons extremely strongly. This allows us to create fluorine-containing materials that would be difficult to imagine with other elements,” explains Plajer.

In their new study, the researchers found that fluorine not only speeds up the polymerization process compared to analogous polyesters without fluorine; it also results in longer polymer chains that entangle more efficiently, making the plastic more mechanically robust.

“What is particularly interesting is that we can selectively replace certain fluorine atoms in the polyester with other molecules. This allows us to precisely control the properties of the polyesters,” explains Plajer.

Additionally, fluoropolyesters offer a sustainable approach, as fluorine can be recovered during a chemical recycling process into a form usable by the chemical industry.

“Our results demonstrate how targeted molecular modifications can fundamentally change the properties of plastics. Integrating fluorine into the polymer structure opens new avenues for developing sustainable, high-performance materials that could meet both environmental requirements and industrial standards,” explains Plajer.