Synthesis and Micellization of Bottlebrush Poloxamers

Joseph F. Hassler, Nicholas J Van Zee, Adelyn A Crabtree, Frank S Bates, Benjamin J. Hackel, Timothy P. Lodge

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Bottlebrush polymers are characterized by an expansive parameter space, including graft length and spacing along the backbone, and these features impact various structural and physical properties such as molecular diffusion and bulk viscosity. In this work, we report a synthetic strategy for making grafted block polymers with poly(propylene oxide) and poly(ethylene oxide) side chains, bottlebrush analogues of poloxamers. Combined anionic and sequential ring-opening metathesis polymerization yielded low dispersity polymers, at full conversion of the macromonomers, with control over graft length, graft end-groups, and overall molecular weight. A set of bottlebrush poloxamers (BBPs), with identical graft lengths and composition, was synthesized over a range of molecular weights. Dynamic light scattering and transmission electron microscopy were used to characterize micelle formation in aqueous buffer. The critical micelle concentration scales exponentially with overall molecular weight for both linear and bottlebrush poloxamers; however, the bottlebrush architecture shifts micelle formation to a much higher concentration at a comparable molecular weight. Consequently, BBPs can exist in solution as unimers at significantly higher molecular weights and concentrations than the linear analogues.

Original languageEnglish (US)
Pages (from-to)460-467
Number of pages8
JournalACS Macro Letters
Issue number4
StatePublished - Apr 19 2022

Bibliographical note

Funding Information:
This work was supported by the National Institutes of Health (R01 HL122323 and R01 AR071349). NMR experiments reported in this publication were supported by the Office of the Director, National Institutes of Health, under Award Number S10OD011952. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The cryo-TEM images were taken using resources in the Characterization Facility, College of Science and Engineering, University of Minnesota, which receives partial support from the NSF through the MRSEC (Award Number DMR-2011401) and the NNCI (Award Number ECCS-2025124) programs. We also thank Dr. Michael Sims from the University of Minnesota for helpful discussions.

Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.

MRSEC Support

  • Shared

PubMed: MeSH publication types

  • Journal Article
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't


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