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Macromolecular metamorphosis via stimulus-induced transformations of polymer architecture


Macromolecular architecture plays a pivotal role in determining the properties of polymers. When designing polymers for specific applications, it is not only the size of a macromolecule that must be considered, but also its shape. In most cases, the topology of a polymer is a static feature that is inalterable once synthesized. Using reversible-covalent chemistry to prompt the disconnection of chemical bonds and the formation of new linkages in situ, we report polymers that undergo dramatic topological transformations via a process we term macromolecular metamorphosis. Utilizing this technique, a linear amphiphilic block copolymer or hyperbranched polymer undergoes ‘metamorphosis’ into comb, star and hydrophobic block copolymer architectures. This approach was extended to include a macroscopic gel which transitioned from a densely and covalently crosslinked network to one with larger distances between the covalent crosslinks when heated. These architectural transformations present an entirely new approach to ‘smart’ materials.

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Figure 1: Transformation of an amphiphilic block copolymer and a segmented hyperbranched polymer into various macromolecular architectures via diene displacement reactions.
Figure 2: Theoretical rationalization of MalOH-based DA reactions and model reactions for the diene displacement approach.
Figure 3: Various reaction pathways of thermally reversible amphiphilic block copolymers.
Figure 4: Topological transformation from linear amphiphilic block copolymer to comb copolymer.
Figure 5: Gel expansion metamorphosis driven by diene displacement.

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This material is based on work supported by the National Science Foundation (DMR-1606410).

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Authors and Affiliations



H.S., A.P.B and B.S.S. conceived and designed the experiments; H.S., C.P.K. and Y.D. performed the experiments; I.G. helped perform and analyse DOSY experiments; H.S., C.P.K. and M.R.H. conducted theoretical calculations; H.S., C.P.K. and M.R.H. analysed and discussed the data; H.S. and C.P.K. prepared all the figures; H.S., B.S.S., C.P.K. and M.R.H. co-wrote the paper.

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Correspondence to Brent S. Sumerlin.

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The authors declare no competing financial interests.

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Sun, H., Kabb, C., Dai, Y. et al. Macromolecular metamorphosis via stimulus-induced transformations of polymer architecture. Nature Chem 9, 817–823 (2017).

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