Triple Effects of Fe3+ for the Integration of Mechanical Robustness, Reprocessability, and Unprecedented Thermal Stability into Polydimethylsiloxane

Abstract

Despite the solution of the recycling difficulty of traditional thermosetting polymers including polydimethylsiloxane (PDMS) with the development of vitrimers, addressing the trade-off among the mechanical, reprocessing, and thermal properties of PDMS remains a scientific challenge. Herein, a novel “one-stone-for-three-birds” structural design strategy based on the triple effects of Fe³⁺ including coordination cross-linking for reinforcement and toughening, catalytic effect on silyl ether exchange for reprocessing, and free radical quenching for thermal stabilization is reported, realizing the integration of mechanical robustness, reprocessability, and unprecedentedly high thermal stability in PDMS for the first time. The PDMS vitrimer in this work exhibits the highest thermal stability among the reported PDMS vitrimers, comparable to commercial PDMS. To elucidate the intrinsic mechanisms of the triple effects of Fe³⁺ in PDMS, multiple characterizations have been performed from the microscopic structure to the macroscopic mechanical, reprocessing, and thermal performances both theoretically and experimentally.