Reducing the number of additives could make plastics easier to recycle
We know the world has a problem with plastic – 370 million tonnes of it produced were produced in 2020 alone. This problem is complex as these versatile materials are a vital part of modern society. Recycling will be one of the main solutions to growing mountains of waste plastic. But there is another facet to this problem – plastics are complex materials in and of themselves, which makes dealing with them at the end of their life that much harder.
Plastics are more than just polymers. To turn polymers into the everyday, indispensable materials we’re familiar with, a range of additives must be formulated with them. These include everything from lubricants to ease processing, to plasticisers to improve flexibility and pigments to impart colour. This is before we even get to the chemistry taking place in plastics themselves, as they are not static mixtures and contain breakdown products, unreacted monomers and manufacturing byproducts. One study identified more than 10,000 additives in use in the plastics that are on the market today. The question is whether such a huge range of different additives is strictly necessary. Probably not. Many will be doing very similar jobs.