Transcript
The world’s landfills and oceans are rapidly filling with plastic. But a breakthrough from scientists at Lawrence Berkeley Lab could finally provide the solution we’ve been waiting for: truly recyclable plastics. A new study, published in Nature Chemistry, details how the researchers were able to discover a new way to assemble plastics and reuse them.
Plastics are made-up of molecules known as polymers that are composed of carbon-containing compounds known as monomers. Once chemicals are added to the plastic for use and consumption, the monomers bind with the chemicals and make it difficult to recycle.
That’s because, when the old plastics are used to make new products, it’s difficult to predict “which properties the new material will inherit from the original plastics. The unpredictability of the properties makes it nearly impossible to enable what is called a “circular economy,” where plastics can be used over and over again for any number of products, including adhesives, phone cases, computer cables and more.
The circular economy and “plastics upcycling” are grand challenges that we’ve talked about in Trends Magazine as well as Business Briefings. But, until now, few plastics have been made to be recycled. But fortunately, the team at Lawrence Berkeley Lab’s Molecular Foundry set out to develop a new way to assemble plastics taking recycling into consideration. And they believe a new type of plastic material known as polydiketoenamine, or PDK, could stem the tide of plastics filling up the natural world. Why? Because the bonds PDK forms are able to be reversed via a simple acid bath yielding only water as a by-product. The recovered monomers can then be re-manufactured into the same polymer formulation, without loss of performance. They can also be turned into other polymer formulations with differentiated properties. The ease with which PDK can be manufactured, used, recycled and re-used—without losing value—points to new directions in designing sustainable polymers with minimal environmental impact.
Although PDK only exists in the lab currently, the researchers are nonetheless excited by what they’ve discovered and the potential positive impact it could have.
With PDKs, the immutable bonds of conventional plastics are replaced with reversible bonds that allow the plastic to be recycled more cost-effectively. This is important because, plastic recycling figures have actually been trending down, making breakthroughs in recyclable plastic all the more important. According to the latest publicly available data, only 9.1 percent of the plastic created in the U.S. in 2015 was recycled. That’s down from 9.5 percent in 2014, according to the EPA.
By making plastic recycling economically viable, this PDK technology promises to finally make the circular-economy a reality.
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