Currently, many of the plastic products that were labeled as biodegradable are only compostable under industrial conditions.
A team of scientists from the University of Bath have found a way to make plastics break down using only ultraviolet light.
Plastic that accelerates its degradation when receiving UV light
As a result of growing public concern about plastic waste, PLA (polylactic acid), created with lactic acid from the fermentation of sugars, is now widely used as a sustainable and renewable alternative to plastics derived from crude oil products, used on a wide variety of products, from disposable cups and tea bags to 3D printing and packaging.
These products are often labeled as biodegradable, however they have limited degradability in natural environments, for example in soil or seawater. Furthermore, it only degrades in high temperature and high humidity industrial composting conditions, something that cannot be achieved in domestic compost heaps.
Now, a team of scientists from the Center for Sustainable and Circular Technologies (CSCT) at the University of Bath have developed a way that could make these plastics more degradable in the natural environment.
The group discovered that they can modify the degradability of the plastic by incorporating different amounts of sugar molecules into the polymer. Specifically, they found that incorporating as few as 3 percent of sugar polymer units into PLA led to a 40 percent degradation within six hours of exposure to ultraviolet light.
Most promisingly, the technology is compatible with existing plastic manufacturing processes, meaning it could be rapidly tested and adopted by the plastics industry.
Publishing in Chemical Communications (open access article), the researchers hope their findings will be used in the future by the plastics industry to help make plastic waste more degradable at the end of product life.
Dr Antoine Buchard, a Royal Society University Research Fellow and CSCT Professor of Polymer Chemistry, led the research, which was supported by the Royal Society.“Most PLA plastics are made of long polymer chains that can be difficult for water and enzymes to break down. Our research adds sugars to polymer chains, linking everything together by bonds that can be broken by ultraviolet light. This could make plastic much more biodegradable in the natural environment, for example in the ocean or in a garden compost heap.”added the teacher and researcher.
Regarding the challenges of this project, Buchard pointed out that “This strategy has yet to be translated into real-life plastic objects and tested in sunlight, but we hope that our technology can be used in the future to make plastics that are strong when used, but can easily break down when reused. and recycling is no longer possible.”
