Scientists turn plastic waste into faster-degrading packaging material

Scientists have developed a new method to convert plastic waste into faster-degrading materials, offering a potential new solution for food packaging sustainability challenges.

Researchers from the University of Edinburgh and RPTU University Kaiserslautern-Landau in Germany say the scalable one-step process can transform commonly used plastics – including materials used in food packaging and 3D printing – into a more readily degradable alternative known as a polythionoester.

The team published the findings in Chem Circularity, and received funding support from UK Research and Innovation (UKRI), the Royal Society, the French National Research Agency and the French National Centre for Scientific Research (CNRS).

The development is significant for the packaging sector because around 99 percent of plastics currently in circulation are not biodegradable, while many existing sustainable alternatives require harsh chemicals or high temperatures to break down effectively.

What makes this discovery so exciting is that we’ve successfully developed a strategy that opens the door to a whole new range of sulfur-containing materials.”

Dr Jennifer Garden from the University of Edinburgh’s School of Chemistry

New route for scalable plastic upcycling

The researchers altered the chemical structure of existing plastics by replacing some oxygen atoms with sulfur atoms using a molecule known as a thionating agent. This creates carbon-sulfur bonds that are weaker than the carbon-oxygen bonds found in conventional plastics, allowing the material to degrade more quickly while also changing its physical properties.

The team tested the process on polycaprolactone, a biodegradable plastic used in food packaging, biomedical implants and 3D printing. Researchers say manufacturers could scale the straightforward process rapidly to convert large quantities of plastic waste into more degradable materials.

The scientists also believe the technique could work with other types of plastic, potentially expanding its use across packaging and manufacturing applications.

“The thionation of polyesters is a challenging task, as these materials are less reactive towards thionation than many other polymers, and accessing polythionoesters via traditional routes can be difficult. What makes this discovery so exciting is that we’ve successfully developed a strategy that opens the door to a whole new range of sulfur-containing materials,” said Dr Jennifer Garden from the University of Edinburgh’s School of Chemistry.

“We’re eager to see where this research takes us and are already looking forward to exploring the many possibilities that this breakthrough has to offer, paving the way for future studies in this promising field.”

Researchers said further studies are needed to understand the environmental impact of the breakdown products created when polythionoesters degrade, as the team explores the technology’s potential across wider plastic applications.