Mechanical and Structural Consequences of Associative Dynamic Cross-Linking in Acrylic Diblock Copolymers

The composition of low-Tg n-butylacrylate-block-(acetoxyaceto)ethyl acrylate block polymers is investigated as a strategy to tune the properties dynamically cross-linked vinylogous urethane vitrimers. As proportion cross-linkable increased, thermorheological properties, structure, and stress relaxation evolve in ways that cannot be explained by increasing cross-link density alone. Evidence presented network connectivity defects such loops dangling ends are increased microphase separation. thermomechanical viscoelastic copolymer-derived vitrimers arise from subtle interplay separation defects.