New plastic breaks down on demand

Indian-origin researchers and colleagues have developed a way to build novel plastics that can be degraded with light after use and turned back into molecules to make new materials.
The discovery by researchers at the North Dakota State University, US holds scientific promise that could lead to a new type of plastic that can be broken down when exposed to a specific type of light and is reduced back to molecules.
The research team, including Mukund Sibi, Sivaguru Jayaraman, Saravana Rajendran, Ramya Raghunathan and Retheesh Krishnan focused on biomass, using oilseed from agricultural crops, cellulose, lignin and sucrose to generate building blocks of molecules that are made into polymers to create plastics.

In their proof of concept experiment, the group used fructose, found commonly in fruit, to create a solution of molecules, which was then converted to a plastic (polymer).
By exposing the plastic to ultraviolet light at 350 nanometres for three hours, researchers degraded the plastic, reducing it back to the soluble building block molecules from which it began.
Plastics usually don't decay for hundreds of years, creating solid waste issues. They generally degrade slowly, potentially leaching chemicals into the environment or creating toxins in the air when burned.

"This cradle-to-cradle approach to create a plastic which can be degraded easily offers scientific potential for eventual products that could lessen dependence on fossil fuels and decrease the amount of raw materials needed," said Dean Webster, professor and chair of the Department of Coatings and Polymeric Materials.

"Our strategy has the potential to build novel materials from biomass that are degradable with light after usage, mitigating the stress of unwanted chemicals in our environment. Studies to address these aspects are currently underway in our laboratories," said Jayaraman.
The study was published in the journal Angewandte Chemie.