Chemically Recyclable Dithioacetal Polymers via Reversible Entropy‐Driven Ring‐Opening Polymerization**

Abstract

AbstractIn a sustainable circular economy, polymers capable of chemical recycling to monomers are highly desirable. We report an efficient monomer‐polymer recycling of polydithioacetal (PDTA). Pristine PDTAs were readily synthesized from 3,4,5‐trimethoxybenzaldehyde and alkyl dithiols. They then exhibited depolymerizability via ring‐closing depolymerization into macrocycles, followed by entropy‐driven ring‐opening polymerization (ED‐ROP) to reform the virgin polymers. High conversions were obtained for both the forward and reverse reactions. Once crosslinked, the network exhibited thermal reprocessability enabled by acid‐catalyzed dithioacetal exchange. The network retained the recyclability into macrocyclic monomers in solvent which can repolymerize to regenerate the crosslinked network. These results demonstrated PDTA as a new molecular platform for the design of recyclable polymers and the advantages of ED‐ROP for which polymerization is favored at higher temperatures.