A discovery 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, which could then be used to create new plastic. The research team focuses 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. “Real sustainability involves breaking it back into the building blocks. We have shown that we can break it down into the building blocks and re-make the polymer,” said Sibi. 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 nanometers for three hours, researchers degraded the plastic, reducing it back to the soluble building block molecules from which it began.
Published in Angewandte Chemie, the proof of concept experiment outlines the work of researchers in the Center for Sustainable Materials Science at North Dakota State University, Fargo. The multidisciplinary team includes researchers from the Department of Chemistry and Biochemistry: Mukund Sibi, university distinguished professor; Sivaguru Jayaraman, James A. Meier professor; postdoctoral fellow Saravana Rajendran; graduate student Ramya Raghunathan; postdoctoral fellow Retheesh Krishnan; and staff scientist Angel Ugrinov; as well as Dean Webster, professor and chair of the Department of Coatings and Polymeric Materials and postdoctoral fellow Ivan Hevus. “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 Sivaguru Jayaraman.
The researchers say further study is needed to evaluate the durability and strength of potential plastics derived from biomass before potential product commercialization could occur. “What is the best trigger to use to break them down? What is the best monomer to use? What is the best polymer we can make?” said Sibi. In the next two years, the group will examine how their process might work with plastics used in cars and electronics, as well as in other items.