It is clear that recycling things like paper, plastic, glass, and metal is better than simply throwing something in the garbage. Using recycled materials is far more environmentally friendly than using virgin materials. But how many times can a single item be recycled?
So far, only one recyclable is able to be recycled endlessly, and that is glass. Paper can be recycled around 4-6 times before it is no longer usable. Plastic can be recycled 7-9 times before it can’t be recycled any more.
That presents a major environmental issue. Every bit of plastic ever created still exists somewhere. Eventually, that plastic will end up in a landfill or, even worse, somewhere in the natural environment.
But a new material created by researchers from the US Department of Energy’s Lawrence Berkeley National Laboratory is fully recyclable, meaning that, like glass, it can be recycled endlessly.
This material is called poly(diketoenamine), or PDK. What sets this material apart from other plastics is its ability to be disassembled at the molecular level and then reassembled into something completely different “without a loss of performance or quality.”
Researchers at Berkeley Lab explain that “with PDKs, the immutable bonds of conventional plastics are replaced with reversible bonds that allow the plastic to be recycled more effectively.”
In order to break apart these bonds, the plastic is placed in an acidic solution. The bonds break down between the monomers, allowing them to be made into completely new polymers.
Researchers believe that PDK can have a wide range of uses, like in textiles, foams, and 3D printing.
“We’re at a critical point where we need to think about the infrastructure needed to modernize recycling facilities for future waste sorting and processing,” said Brett Helms, a staff scientist at Berkeley Lab’s Molecular Foundry. “If these facilities were designed to recycle or upcycle PDK and related plastics, then we would be able to more effectively divert plastic from landfills and the oceans.”
“This is an exciting time to start thinking about how to design both materials and recycling facilities to enable circular plastics,” said Helms.