Atom Transfer Radical (ATR) Depolymerization of Polystyrene

Abstract

Polymers are essential materials across various industries and are being used in daily life. However, due to their resistance towards degradation, they started accumulating in the environment or leaking into the ocean, polluting the Earth. To mitigate these issues, it’s essential to enhance sustainability through the development of improved recycling methods. This research investigates the application of Atom Transfer Radical Depolymerization (ATRdP) to depolymerize polystyrene (PS) into its monomeric unit, styrene, followed by repolymerization to establish a fully circular process. By utilizing ATRdP's reversible nature, this approach offers a promising, environmentally friendly, cost-effective solution to depolymerize waste PS. The Cu(I)Br/TPMA catalyst system is employed for both depolymerization and repolymerization. Additionally, an alternative method using Cu(II)Cl₂ is investigated, wherein an amine ligand facilitates the in-situ reduction of Cu(II) to Cu(I) at elevated temperatures, enables effective depolymerization. This work advances the development of sustainable polymer recycling strategies, contributing to a circular economy of plastics.