Vitrimer Nanocomposites from PISA

Thi H. Le^‡, Kevin A. Stewart^‡, Cabell B. Eades, Jared I. Bowman, Nathan B. Wei, Brent S. Sumerlin

University of Florida

Vitrimers, or associative covalent adaptable networks (CANs), offer a promising avenue for closed-loop recyclability over traditionally non-recyclable thermosets. However, the dynamicity of reversible crosslinks within CANs renders the materials susceptible to creep deformation. In this study, we address this challenge by integrating core-crosslinked, spherical nanoparticles derived from polymerization-induced self-assembly (PISA) into vitrimer networks. The resulting dual-crosslinked system, characterized by embedded nanospheres, exhibits enhanced creep resistance over networks derived from a linear block copolymer counterpart. The spherical nanoparticles effectively impede chain mobility, thereby hindering creep deformation via bond exchange. Furthermore, the degree of polymerization within the core-forming block serves as an effective strategy for controlling flow behavior at service temperatures. These findings demonstrate the mutually inclusive collaboration of spherical nanoparticles and dually crosslinked CANs, facilitated by PISA, in tailoring the viscoelastic profile of dynamic thermosets. Notably, the integration of PISA paves the way for the construction of novel CANs with preordained phase separation and microstructure, enabling strong thermomechanical performance, facile reprocessability, and inherent tunability.