2022 Annual Meeting

(560h) Tunable, Phase-Separated Dynamic Networks through Thia-Michael Chemistry

Authors

Neil Dolinski - Presenter, University of Chicago
Ran Tao, NIST
Nicholas Boynton, University of Chicago
Anthony Kotula, National Institute of Standards and Technology
Charlie Lindberg, University of Chicago
Stuart J. Rowan, University of Chicago
Dynamic covalent networks (DCNs) are a broad class of polymeric materials containing covalent crosslinks that undergo exchange reactions (ideally in a reversible fashion). By changing the molecular exchange dynamics, the network relaxation properties can be directly manipulated. In this talk, recent advancements in DCNs comprised of strongly tunable, catalyst-free, ambient temperature dynamic thia-Michael (tM) bonds are detailed. While the ambient dynamic exchange would typically result in weak materials, tM DCNs undergo an emergent dynamic reaction-induced phase separation process (DRIPS) that leads to robust mechanical properties. The underlying morphology of phase-separated domains, as well as user-defined modulation of the (thermo)mechanical properties and stress relaxation behavior through electronic substituents, are highlighted through a diverse suite of characterization techniques (NMR kinetics, AFM, Raman-coupled rheology, and stress relaxation experiments).