A simple chemistry trick could end forever plastic
Seeing plastic trash while hiking inspired a Rutgers chemist to rethink why synthetic plastics last forever while natural polymers don’t. By mimicking tiny structural features used in DNA and proteins, researchers designed plastics that remain durable but can be triggered to fall apart naturally. The breakdown speed can be precisely tuned, from days to years, or switched on with light or simple chemical signals. The discovery could reshape everything from food packaging to medicine delivery.
Yuwei Gu was walking through Bear Mountain State Park in New York when an unexpected sight caught his attention. Plastic bottles were scattered along the trail, with more drifting across a nearby lake. Seeing plastic waste in such a natural setting stopped the Rutgers chemist in his tracks and set his mind racing.
Gu began thinking about polymers, long chainlike molecules that make up both natural materials and modern plastics. DNA and RNA are polymers, and so are proteins and cellulose. The difference is that nature's polymers eventually break down, while synthetic plastics often remain in the environment for decades or longer.
"Biology uses polymers everywhere, such as proteins, DNA, RNA and cellulose, yet nature never faces the kind of long-term accumulation problems we see with synthetic plastics," said Gu, an assistant professor in the Department of Chemistry and Chemical Biology in the Rutgers School of Arts and Sciences.
Standing there in the woods, the reason suddenly became clear to him.
"The difference has to lie in chemistry," he said.
Copying Nature's Built-In Exit Strategy
Gu realized that if natural polymers can perform their function and then disappear, human-made plastics might be able to do the same. He already knew that biological polymers contain small built-in chemical features that help their bonds break apart at the right moment.
"I thought, what if we copy that structural trick?" he said. "Could we make human-made plastics behave the same way?"
That question led to a breakthrough. In a study published in Nature Chemistry, Gu and his Rutgers colleagues showed that using this nature-inspired approach allows plastics to break down under everyday conditions, without requiring high heat or harsh chemicals.
"We wanted to tackle one of the biggest challenges of modern plastics," Gu said. "Our goal was to find a new chemical strategy that would allow plastics to degrade naturally under everyday conditions without the need for special treatments."
How Polymers and Chemical Bonds Work
Polymers are made of many repeating units linked together, much like beads on a string. Plastics fall into this category, as do DNA, RNA and proteins. DNA and RNA consist of chains of smaller units known as nucleotides, while proteins are built from amino acids.
What holds these units together are chemical bonds, which act like glue at the molecular level. In polymers, these bonds connect one building block to the next. Strong bonds give plastics their durability, but they also make them difficult to break down once discarded. Gu's research focused on designing bonds that stay strong during use but become easier to break later when degradation is desired.
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