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A new type of plastic developed by chemical engineers in the United Kingdom can be broken down into a gas with relatively little heat and then re-form itself into the same material as it cools, offering a potential new approach to recyclable and reusable plastics.
The proof-of-concept material, developed by researchers at the University of Surrey, is made from poly(1,2-dithiolane), a polymer built from ring-shaped molecules containing carbon, hydrogen, and linked sulfur atoms. Its unusual chemical structure allows the material to repeatedly break apart and reform.
The findings, published in Macromolecules, show that the polymer begins to break down at about 90 degrees Celsius, or roughly 194 degrees Fahrenheit. Unlike conventional plastics that generally require much higher temperatures and can produce unwanted byproducts during processing, the new material sublimates directly from a solid into a gas.
Peter Roth, a chemical engineer at the University of Surrey, said the researchers wanted to demonstrate that plastics could be designed with fundamentally different end-of-life properties. Rather than remaining stable indefinitely, the material can be converted into vapor and subsequently rebuild itself into the original polymer.
The researchers demonstrated one potential application by coating rolled filter paper with the polymer. The resulting layer made the paper resistant to water. When heated, the coating could be removed, allowing the paper to regain its ability to absorb water, while the polymer itself re-formed after cooling.
The reversible process could also have applications in recycling. In one experiment, the researchers incorporated Nile red dye into the polymer and then removed the additive through heating. Conventional plastic recycling can require additional chemical processing to separate additives and contaminants, making the process more expensive and resource-intensive.
The technology is still far from replacing common plastics such as polyethylene, the world’s most widely produced plastic. The researchers also emphasize that their material is not a solution to the global plastic waste crisis.
Instead, the work demonstrates a different design philosophy for polymers, particularly materials used as protective coatings. Such coatings are widely used to provide resistance to moisture, corrosion, wear and other environmental stresses.
Lead author Touseef Kazmi said the research demonstrates a previously unavailable approach and could eventually help scientists develop materials that are easier to apply, remove and recycle.
For now, the polymer remains a laboratory proof of concept. Turning its unusual behavior into a commercially viable material will require further research into its performance, durability and scalability.
