From Macromolecular Construction to Unbuilding Polymers: Strategies for Greater Circularity Through (De)Polymerization Catalysis

Prof. Dr. Daniel Taton, Universität Bordeaux

The transition toward sustainable materials requires not only inventing new polymers that are easily degradable by design, but also finding ways to break down existing ones that resist any form of (bio)chemical recycling. In this lecture, will be presented complementary bottom-up and top-down strategies aimed at rethinking the chemical life cycle of polymers through the lens of sustainable macromolecular chemistry. On the bottom-up side, it will be shown how organocatalyzed group transfer polymerization (O-GTP) enables the controlled synthesis of bio-based polymuconates, offering a unique platform that combines structural tunability, post-polymerization modification, and programmed chemical degradability. On the top-down side, will be discussed both photo- and bio-catalytic methods in view of triggering the oxidative depolymerization of polystyrene (PS), one of the most recalcitrant commodity plastics. This can be achieved either through visible-light-driven upcycling of PS into benzoic acid as an added value chemical, or through enzyme-mediated depolymerization of PS formulated into colloidally stable nanoparticles in aqueous media. These different approaches illustrate a unified vision: leveraging macromolecular control, whether in the synthesis, modification, or degradation of polymers, with the aim of better managing their end of life, more in line with the principles of a circular economy for materials.