(378b) Dynamic Covalent Photopolymer Networks for Additive Manufacturing

Covalent adaptable networks (CANs) leverage exchangeable bonds to enable reconfigurability and recyclability of cross-linked polymer networks. Recently, this paradigm has been extended to additive manufacturing, where triggering dynamic chemistry can be leveraged to both extend the life of printed parts through self-healing or plasticity, while also facilitating life cycle control through exchange-mediated degradation. In this work, we introduce a method to incorporate associative exchange chemistry within photopolymer resins that are amenable to stereolithographic additive manufacturing. We show that through judicious selection of resin components, parts can be printed that range from tough thermoplastic-like materials to soft, resilient elastomers. Significantly, incorporation of dynamic bonds facilitates degradation into low viscosity oligomers under mild conditions. These oligomers can subsequently be re-incorporated into new printed parts of targeted composition, mechanical properties, and function. Finally, we demonstrated that dynamic bonds also engender advanced capabilities within printed parts, such as shape memory through exchange-induced plasticity and self-healing of damaged components.