Amino Acid-based Dithiolactone Monomers towards Chemically Recyclable Polymers

Developing chemically recyclable polymers represents a greener alternative to landfill and incineration and offers a closed-loop strategy toward a circular materials economy. Although some progress has been achieved in the synthesis of closed-loop recycled polymers, the synthesis of chemically recyclable polymers is still plagued with certain fundamental limitations, including trade-offs between the monomer's cyclizability and polymerizability, as well as between polymer's depolymerizability and properties. Very recently, our research group has proposed that amino acid-based dithiolactone monomers is a kind of "ideal monomer" for chemically recyclable polymers. These dithiolactone monomers demonstrate appealing chemical properties different from those of dilactone, including accelerated ring closure, augmented kinetics polymerizability, high depolymerizability and selectivity, and thus constitute a unique class of polythioester materials exhibiting controlled molecular weight (up to 100.5 kDa), atactic yet high crystallinity, structurally diversity, and chemical recyclability. In particular, the ring-opening polymerization of isopropyl dithiolactone derived from valine, delivered atactic yet crystalline polythioester. These amino acid-based chemically recyclable plastics show promise as next-generation sustainable materials. [GRAPHICS]