Thermally Induced Macromolecular Sequence Inversion in Triblock Copolymers and Terpolymers

Dynamic control over polymer sequences remains a major challenge in synthetic macromolecules, limiting their adaptability relative to biomacromolecules. Herein, we introduce an intra-macromolecular sequence inversion in triblock copolymers and terpolymers using a furan-maleimide-anthracene Diels-Alder system, enabling thermal reconfiguration at 120°C without altering composition or molecular weight. Bifunctional initiators bearing reversible Diels-Alder linkages allow the synthesis of symmetric (ABA) and asymmetric (ABC) triblock co/terpolymers. Upon heating, retro-Diels-Alder dissociation followed by anthracene-maleimide (Anth-Mal) cycloaddition induces sequence inversion, yielding BAB or BAC architectures. Comprehensive experimental characterization confirms preservation of chain integrity, while revealing altered diffusion coefficients and distinct microphase-separated morphologies, highlighting the pronounced influence of sequence on polymer properties. This strategy establishes a paradigm for programmable polymer metamorphosis, opening new avenues toward stimuli-responsive materials with tunable self-assembly, crystallinity, and mechanical properties.