By selectively extracting hydrogen atoms from the Polyolefin, the chemists devised a way to extend the life of single-use plastic into a high-value plastic known as an ionomer.
Chemists at the University of North Carolina at Chapel Hill have created a method to create stronger plastics from the recycling process. This is a development that could boost recycling rates, at least in the United States, since the material obtained with this process would potentially be more valuable than the original.
The recycling problem
Despite the fact that more and more industries are opting for environmentally friendly processes, the recycling rate in the United States (the country that generates the most plastic waste in the world) is barely 9%.
This percentage is because the chemistry of most plastics today makes them difficult and expensive to recycle. Even thermoplastics, explains the University of North Carolina, weaken with each reuse. Generally speaking, there are no large profit incentives for recycling plastics.
To tackle this problem, chemists Frank Leibfarth and Erik Alexanian collaborate on an innovative method of recycling plastic.
“Our approach sees plastic waste as a potentially valuable resource for the production of new molecules and materials,” said Frank Leibfarth, an assistant professor of chemistry in the UNC College of Arts and Sciences. “We hope that this method can create an economic incentive to recycle plastic, literally turning trash into treasure.”
According to a report published in the journal Science, the key to extending the useful life of polymers lies in the modification of their carbon-hydrogen bonds. With a newly identified reagent that could remove hydrogen atoms from medicinal compounds and polymers, UNC chemists were able to create new bonds in places previously considered nonreactive.
“The versatility of our approach is that it enables many valuable transformations of carbon-hydrogen bonds in a wide range of important compounds,” Alexanian noted.
Create better plastics with recycling
The researchers worked with plastic foam packaging used to protect electronics during shipping that typically end up in landfills. Samples of post-consumer foam made from commercial Polyolefin were provided by High Cube LLC, a Durham, North Carolina recycling company.
By selectively extracting hydrogen atoms from the Polyolefin, the chemists devised a way to extend the life of the single-use plastic into a high-value plastic known as an ionomer. Popular ionomers are Dow’s SURLYNTM, a benchmark material used in a wide variety of food packaging.
While most recycled plastic is “recycled” into lower-quality products, like polyester carpet or clothing, which can still end up in landfills, the chemistry can be repeatedly applied to polymers to help recycle them over and over again and ” it could change the way we see plastic,” Leibfarth said.
