TY - JOUR
T1 - Densely Arrayed Cage-Shaped Polymer Topologies Synthesized via Cyclopolymerization of Star-Shaped Macromonomers
AU - Mato, Yoshinobu
AU - Sudo, Maho
AU - Marubayashi, Hironori
AU - Ree, Brian J.
AU - Tajima, Kenji
AU - Yamamoto, Takuya
AU - Jinnai, Hiroshi
AU - Isono, Takuya
AU - Satoh, Toshifumi
N1 - Funding Information:
This work was financially supported by the MEXT Grant-in-Aid for Challenging Exploratory Research (19K22209), Grant-in-Aid for Scientific Research (A and B) (19H00905 and 19H02769), Grant-in-Aid for Scientific Research on Innovative Areas “Hybrid Catalysis” (18H04639 and 20H04798), JST CREST (Grant Number JPMJCR19T4), Photo-excitonix Project (Hokkaido University), and the Creative Research Institute (CRIS, Hokkaido University). Y.M. was funded by a JSPS Fellowship for Young Scientists.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/10/12
Y1 - 2021/10/12
N2 - This work reports a facile and versatile ring-opening metathesis polymerization of three- and four-armed star-shaped poly(ϵ-caprolactone) (PCL) macromonomers bearing a norbornenyl group at each chain end using Grubbs' third-generation catalyst under diluted condition to obtain graft polymers (GPs) comprising densely arrayed three- and four-armed cage-shaped grafted PCLs (GPCLs) with narrow dispersity (1.19-1.35) and a controllable number of cage repeating units up to 40 (molecular weight: ∼320 »000 g mol-1). The GPCLs were characterized using nuclear magnetic resonance spectroscopy, size exclusion chromatography, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The cyclopolymerization proceeded via repetitive rapid intramolecular reactions to form cage-shaped units followed by slow intermolecular propagation. This synthesis was applicable to star-shaped poly(l-lactide), poly(trimethylene carbonate), and poly(ethylene glycol). Investigating the structure-property relationships regarding crystallization behavior, hydrodynamic diameter, and viscosity revealed that cage-shaped topological side chains reduced the chain dimensions and mobility compared to their linear and cyclic counterparts.
AB - This work reports a facile and versatile ring-opening metathesis polymerization of three- and four-armed star-shaped poly(ϵ-caprolactone) (PCL) macromonomers bearing a norbornenyl group at each chain end using Grubbs' third-generation catalyst under diluted condition to obtain graft polymers (GPs) comprising densely arrayed three- and four-armed cage-shaped grafted PCLs (GPCLs) with narrow dispersity (1.19-1.35) and a controllable number of cage repeating units up to 40 (molecular weight: ∼320 »000 g mol-1). The GPCLs were characterized using nuclear magnetic resonance spectroscopy, size exclusion chromatography, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The cyclopolymerization proceeded via repetitive rapid intramolecular reactions to form cage-shaped units followed by slow intermolecular propagation. This synthesis was applicable to star-shaped poly(l-lactide), poly(trimethylene carbonate), and poly(ethylene glycol). Investigating the structure-property relationships regarding crystallization behavior, hydrodynamic diameter, and viscosity revealed that cage-shaped topological side chains reduced the chain dimensions and mobility compared to their linear and cyclic counterparts.
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U2 - 10.1021/acs.macromol.1c01230
DO - 10.1021/acs.macromol.1c01230
M3 - Article
AN - SCOPUS:85116600895
SN - 0024-9297
VL - 54
SP - 9079
EP - 9090
JO - Macromolecules
JF - Macromolecules
IS - 19
ER -