Electrochemical Chlorine Shuttle from PVC Waste to Vinyl Ether Acceptors for the Synthesis of Biodegradable Polyester Precursors

Poly(vinyl chloride) (PVC) remains one of the most widely produced polymers globally but poses significant environmental and energetic challenges due to its high chlorine content, low recyclability, and the energy-intensive nature of both production and disposal. Here, a sustainable electrochemical approach is reported for the dechlorination of PVC and simultaneous synthetic generation of cyclic acetals, precursors for biodegradable polyesters, employing a Cl$_2$-shuttle reaction onto vinyl ethers. By systematic electrochemical screening and a Design of Experiments (DoE) optimization strategy, high yields of cyclic acetal formation and elevated dechlorination rates of up to 94% for PVC are achieved. The resulting polymer retains its structural integrity and exhibits internal plasticization via covalent recombination with phthalate plasticizer fragments. This shows that beyond chlorine recovery, the process opens up attractive upcycling pathways through tunable thermal properties of partially dechlorinated PVC. Additionally, our method is tolerant to common plastic additives and applicable to real PVC waste streams, highlighting its robustness and industrial potential. The broad scope of accessible cyclic acetals expands the utility of the reported process using PVC as a chlorine source, providing a platform to produce valuable monomer precursors and enabling facilitated access to versatile, biodegradable polyester materials.