One cheap chemical turns old plexiglass into 98% new material

Researchers at ETH Zurich have found a way to break acrylic glass back into its original building blocks, recovering up to 98% of the material as pure monomers. The method, published in Nature Chemistry, uses a single inexpensive chemical already on the market and no solvents. The reaction starts at just over 200 degrees Celsius, about half the heat older recycling methods demanded. Acrylic glass, sold under the brand name Plexiglas, fills windows, car taillights, and protective barriers, and most of it has ended up as waste because earlier recycling was too costly or complicated for companies to bother with. The recovered material came out pure enough for new products even when the original plastic was dyed or full of impurities. Because the process runs on existing equipment, firms would not need expensive overhauls. "What makes our new approach so exciting is its simplicity," said lead author Richard Whitfield. The team hopes it can one day work on polystyrene too.