A team at ETH Zurich in Switzerland, led by Professor Athina Anastasaki, has developed an economically viable way to recycle acrylic glass, the material known as Plexiglas. The work was published in Nature Chemistry.
The method uses a single cheap, commercially available reagent and no solvents to break the plastic down into its monomers, the small molecules it is made from. Breakdown starts just above 200 °C, whereas at least 400 °C was needed until now.
Yields reach 98% and the recovered monomers are very pure, even when the acrylic contains dyes or impurities. They can be used to make new plastic of the same quality as the original. Pyrolysis, the usual alternative, leaves up to 3% impurities.
ETH has filed a patent and is looking for companies to license the technique, which can use existing infrastructure. The team now wants to scale it up and try the same principle on polystyrene; for now, the method works only with acrylic glass.
