Researchers discover a way to recycle one of the most problematic plastics
Plastics are incredibly useful but dangerously problematic. Our planet is drowning in unrecycled plastic, and we need better ways to recycle to help it recover.
In theory, all plastics can be recycled, but the sad reality is that the vast majority never get recycled. This is due to the cost of collecting, cleaning, and sorting the thousands of types of plastics before they begin their recycling processes. Even though global recycling rates are barely at 5%, current projections show that global plastic waste is on course to triple by 2060. Polyvinyl chloride, commonly known as PVC, is the third most-produced plastic in the world and one of the most difficult to recycle. The high versatility of PVC has led to its use in a wide variety of products, including hospital equipment, plumbing, electrical wiring, packaging, and even clothing. Unfortunately, less than a quarter of 1% of post-consumer PVC is currently recycled.
Thanks to a research team at the University of Michigan, there is now a promising new technique to recycle PVC.
The team at the University of Michigan led by Danielle Fagnani and Anne McNeil has discovered a way to use a component of the PVC that previously made recycling incredibly difficult by improving the method's efficiency. The components that make PVC so difficult to recycle are the various additives it can contain called plasticizers. Plasticizers are compounds added in the production process to make PVC more flexible and durable. Fagnani stated in a recent interview, “PVC usually contains a lot of plasticizers, which contaminate everything in the recycling stream and are usually very toxic. It also releases hydrochloric acid really rapidly with some heat.”
The most detrimental of the plasticizers are phthalates, which are highly toxic to humans and known to negatively impact our hormonal systems. When plastics are recycled by adding heat, the phthalates leach out. The method discovered by Fagnani and her team uses the toxic phthalates to decrease the energy input required and make the process more efficient overall.
They did this by implementing an electrochemistry technique. Electrochemistry is the use of electrical energy to bring about non-spontaneous chemical reactions. This approach doesn’t require heat and allowed the researchers to more precisely control the speed of the reaction and the amount of hydrochloric acid being produced. The team noted that the chemical byproduct produced by this technique can be used in subsequent chemical reactions. This new recycling technique is not perfect, but it shows how recycling efficiency can be improved.
This discovery has massive implications for the recycling industry. PVC requires less energy to produce than almost all other plastics, and this discovery could be the first step to making PVC highly recyclable. If research continues and the efficiency of this technique can be improved at scale, it will be massively significant in raising the concerningly low recycling rates of plastics.
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