Cyclic Block Copolymers via Ring Expansion Metathesis Polymerization
- 1Department of Chemistry and Molecular Engineering & Science Institute
- 2University of Washington
Abstract
Cyclic block copolymers are a captivating class of macromolecules with the potential for advanced materials applications due to their distinctive self-assembly behavior. Ring expansion metathesis polymerization (REMP) is a promising method towards such high molar mass cyclic polymers, but uncontrolled intermolecular ring-transfer processes have precluded its extension to cyclic block copolymers synthesis. As a result, the synthesis of cyclic block copolymers remains exceedingly rare. In this work, we utilize newfound living characteristics of REMP with cyclic Ru-benzylidene initiator Pyr-CB6 to develop novel block copolymerization methodology. Using an operationally simple sequential monomer-addition strategy followed by thermally triggered intramolecular backbiting, we produce cyclic multiblock copolymers of low dispersity (<1.2) and high yields (up to 97%). Mechanistic analyses elucidate the delicate role that pyridine plays in the polymerization process. As a metathesis inhibitor, pyridine makes intermolecular ring-transfer prohibitively slow, but permits intramolecular backbiting when triggered. Overall, this study demonstrates the power of REMP with Pyr-CB6 as a vehicle towards a diverse future of cyclic block copolymer materials and applications.
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BibTeX
@misc{miller2026cyclic,
title = {{Cyclic Block Copolymers via Ring Expansion Metathesis Polymerization}},
author = {Lucy P Miller and Matthew R Golder},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.10002042/v2},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.10002042/v2},
note = {CC BY},
}
RIS
TY - UNPB
TI - Cyclic Block Copolymers via Ring Expansion Metathesis Polymerization
AU - Lucy P Miller
AU - Matthew R Golder
PY - 2026
DA - 2026/10/02
PB - ChemRxiv
DO - 10.26434/chemrxiv.10002042/v2
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.10002042/v2
AB - Cyclic block copolymers are a captivating class of macromolecules with the potential for advanced materials applications due to their distinctive self-assembly behavior. Ring expansion metathesis polymerization (REMP) is a promising method towards such high molar mass cyclic polymers, but uncontrolled intermolecular ring-transfer processes have precluded its extension to cyclic block copolymers synthesis. As a result, the synthesis of cyclic block copolymers remains exceedingly rare. In this work, we utilize newfound living characteristics of REMP with cyclic Ru-benzylidene initiator Pyr-CB6 to develop novel block copolymerization methodology. Using an operationally simple sequential monomer-addition strategy followed by thermally triggered intramolecular backbiting, we produce cyclic multiblock copolymers of low dispersity (<1.2) and high yields (up to 97%). Mechanistic analyses elucidate the delicate role that pyridine plays in the polymerization process. As a metathesis inhibitor, pyridine makes intermolecular ring-transfer prohibitively slow, but permits intramolecular backbiting when triggered. Overall, this study demonstrates the power of REMP with Pyr-CB6 as a vehicle towards a diverse future of cyclic block copolymer materials and applications.
ER -