Polynorbornene‐g‐poly(ethylene oxide) Through the Combination of ROMP and Nitroxide Radical Coupling Reactions

Abstract

Grafting‐onto and grafting‐through strategies for preparing polynorbornene‐g‐poly(ethylene oxide)s (PNB‐g‐PEO) have been developed through a combination of ring‐opening metathesis polymerization (ROMP) and nitroxide radical coupling (NRC). 2‐Bromoisobutyrate‐functionalized poly(ethylene oxide) monomethyl ether 2000 (PEO45‐Br) was successfully anchored on a 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy (TEMPO)‐containing polynorbornene backbone of number‐average degree of polymerization (trueitalicDPn¯) of 100 through the grafting‐onto strategy, resulting in PNB‐g‐PEO with a grafting yield ranging up to 90%. ROMP of ω‐exo‐norbornenyl PEO45 monomethyl ether macromonomer issued from NRC between a nitroxide‐functionalized norbornene and PEO45‐Br has allowed to reach a well‐defined bottlebrush copolymer with a backbone trueitalicDPn¯ of 100 while retaining a low dispersity of 1.09. The effect of the grafting‐onto versus grafting‐through strategy and, consequently, of the grafting density, was investigated by thermal analyses and self‐assembly properties of the PNB100‐g‐PEO45. A substantial reduction of crystallinity was observed for PNB‐g‐PEO prepared via the grafting‐through route. Preliminary study of the self‐assembling properties has shown that the graft copolymers form monodisperse spherical particles in aqueous solution. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 645–653

Impact of bottlebrush chain architecture on Tg‐confinement and fragility‐confinement effects enabled by thermo‐cleavable bottlebrush polymers synthesized by radical coupling and atom transfer radical polymerization

“…To the best of our knowledge, there has been no previous report in the refereed literature on the T g ‐confinement behavior of bottlebrush polymer in nanoscale thick films. With advancements in synthetic techniques over the past two decades, a wide range of bottlebrush polymers have been synthesized [ 53–87 ] and various potential applications have been advanced based on bottlebrush structures and properties, [ 82–88 ] for example, polymer photonics, [ 82 ] supersoft/superelastic materials, [ 83–85 ] self‐assembly for nanopatterning, [ 86 ] and artificial tissues that are both firm and soft. [ 87 ] Thus, investigating bottlebrush behavior under conditions of nanoscale confinement may be important not only for advancing the scientific understanding of polymer topology‐property effects, including confinement effects, but also for advancing the applications of bottlebrushes.…”

Modeling and Simulation of Polymerization Processes

“…[219] Polynorbornene-g-poly(ethylene oxide) through the combination of ROMP and nitroxide radical coupling reactions. [220] Potent bioactive bone cements impregnated with polystyrene-g-soybean oil-AgNPs for advanced bone tissue applications. [221] Fabrication of cellulose nanocrystal-g-poly(acrylic acid-co-acrylamide) aerogels for efficient Pb(II) removal.…”