Programmable Mechanical Properties in Dynamic Reaction-Induced Phase Separated Thia-Michael Networks

A series of dynamic covalent network films containing the catalyst-free, reversible thia-Michael bond were used to understand structure/property/processing relationships in materials that exhibit dynamic reaction-induced phase separation (DRIPS). By controlling both crosslinking density and thermal processing conditions of the networks, a range of morphological, rheological, and mechanical properties were realized. Critically, this system uses thermal processing as the sole handle to access a wide range of mechanical properties with a single variant of Michael acceptor, instead of tuning the electron-donating/withdrawing nature of the Michael acceptor. Furthermore, it was demonstrated that different shape-memory behavior can be programmed into a material through straightforward thermal processing.