Polydiketoenamine, a plastic developed by scientists at the Lawrence Berkeley National Laboratory, can allow efficient and indefinite recycling
Scientists at the Lawrence Berkeley National Laboratory have developed a system that enables the recycling of post-consumer mixed-use plastics, materials that are traditionally difficult to recycle.
The researchers also managed to develop a custom-engineered material called Polydiketoenamine (PDK), a new type of plastic they developed for efficient and indefinite recycling.
As detailed in an article published in the technical journal Science Advances by the American Association for the Advancement of Science, the material derived from the mixed plastic precursor should pave the way for a broader range of fully recyclable plastic products and enable a circular economy. efficient for durable goods, such as automobiles.
“We generate staggering amounts of plastic and plastic-containing products every year, but only a small fraction of that plastic can be recovered and used to make products of similar quality,” explained Dr. Brett Helms, staff scientist at Berkeley Lab’s Molecular Foundry. .
“That’s because most products, from food packaging films and single-use bags to sneakers and electronics, are made from mixes of different plastics. Once mixed, those plastics cannot be recovered and used to make new bags or shoes. Instead, most [plastic] ends up in landfills, incinerators, or the oceans,” he added.
The mixed plastics challenge
According to Berkeley Lab scientists, the new Polydiketoenamine (PDK), a new type of plastic they developed for efficient and indefinite recycling, will provide a low-carbon manufacturing solution for plastic products that no longer have to go to a landfill.
Different PDK plastics in an acid solution have shown how each polymer readily breaks down into individual monomers in different steps performed at different temperatures, allowing complete recycling of both plastics.
In the Science Advances article, the researchers describe the process as follows. “PDK resins deconstruct as solids in the presence of metals and glass, avoiding the high-cost melt filtration step required to recycle basic plastics. At each stage of the thermally controlled recycling process, we recover specific monomers, additives, and fillers from PDK resins in blends, laminates, or mixed PDK assemblies that are indistinguishable from the associated primary raw materials and reusable in closed-loop material lifecycles.” .
“We now know how to adapt PDK plastics to recycle complex products that comprise multiple types of materials,” Helms explained to PlasticsToday. “An example could be a shoe, where a textile is attached to a rubber using an adhesive. Conventional materials used in such products cannot be recycled for reuse as they cannot be independently deconstructed. However, if they were made from different specially designed PDK polymers, they could be [deconstructed] for the first time.”
