Most plastics have a chemical history that makes starting a new life a challenge. The dyes and flame retardants that make them perfect for say, a couch cushion or a bottle of detergent, make them tough to transform into a desirable end product—one of the reasons just 10% of plastic in the United States gets recycled. Now, researchers have created a plastic with a special chemical bond that helps it separate out from those additives, turning it back into a pure, valuable product that can be reused again and again.
To make the new material, researchers tweaked a type of vitrimer, a glasslike plastic developed in 2011, by adding molecules that change the chemical bonds holding it together. These new bonds, called dynamic covalent diketoenamine bonds, require less energy to break than those in traditional plastics.