Block Copolymer Vitrimers.

In this report, we merge block copolymers with vitrimers in an effort to realize the prospect of higher-order, nanoscale control over associative cross-link exchange and flow. We show the use of controlled polymerization as a vital tool to understand fundamental structure-property effects through the precise control of polymer architecture and molecular weight. Vitrimers derived from self-assembling block copolymers exhibit superior resistance to macroscopic deformation in comparison to their analogs generated from statistical copolymers. Our results suggest that the enhanced creep resistance achieved by control over chain topology in block vitrimers can be used to tune viscoelastic properties. The resistance to macroscopic deformation that arises from a microphase-separated structure in this new class of materials differentiates block vitrimers from their statistical counterparts and introduces the potential of topology-control over viscoelastic flow.