Chemical Recycling of Multiblock Copolymers to Polyols via Degradable Acetal Junctions

Developing polymer systems that maintain mechanical performance during use while enabling efficient chemical recycling at end-of-life remains a significant challenge. Herein, we report a rapid, metal-free approach to the synthesis of acetal-linked multiblock copolymers via acid-catalyzed coupling of hydroxyl-terminated polyols. Coupling of poly( l -lactide) (PLLA) and poly(propylene carbonate) (PPC) with divinyl ethers rapidly affords high-molecular-weight multiblock copolymers ( M w ≈ 10 5 g/mol) on a subhour time scale under mild conditions. Systematic variation of block length and composition enables precise control over polymer architecture and corresponding mechanical properties of PLLA/PPC multiblock copolymers. Moreover, the versatility of this strategy is demonstrated by incorporating alternative polyols, including poly(ε-caprolactone) (PCL) and poly(trimethylene carbonate) (PTMC), in place of PPC. Importantly, the acetal junctions undergo rapid and selective cleavage under mild acidic conditions, enabling high-purity recovery of the parent polyols within minutes. The recovered polyols can be reused to regenerate multiblock copolymers with comparable molecular weights and mechanical performance, thereby establishing an efficient platform for structurally tunable and chemically recyclable multiblock materials.