Entropy-driven toughening and closed-loop recycling of polymers via divergent metal-pyrazole interactions.

ABSTRACT: Developing dynamic polymeric materials that possess closed-loop recyclability under mild conditions and outstanding mechanical properties is a highly desirable but challenging pursuit. This study presents a entropy-driven toughening strategy through divergent metal-pyrazole (DiMP) coordinations, achieving a mechanically robust and recyclable polyurethane (PU) elastomer. DiMP interactions feature multiple discrete complexes (i.e., CuL₂, Cu₂L₂, and CuL₃, where L = dipyrazole ligand) to minimize the entropy-gain mediated compensatory effect during bond dissociation and accordingly increase energy dissipation upon polymer deformation. The DiMP-crosslinked PUs (DiMPUs) exhibit an unprecedented 11-fold improvement in toughness (310.8 MJ m^-3)

SUBMITTER: Huang L 

PROVIDER: S-EPMC12661056 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature