Synthesis of Cellulosic Bottlebrushes with Regioselectively Substituted Side Chains and Their Self‐assembly

Sakakibara, Keita; Kinose, Yuji; Tsujii, Yoshinobu

doi:10.1002/9781119217619.ch3

Cited by 3 publications

(4 citation statements)

References 28 publications

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“…previously, 26 and a detailed characterization is given. First, to yield 6, successful esterification of the residual hydroxy groups of 4 with PEG-I followed by complete deprotection of the MeOTr group with HCl was confirmed using the 1 H NMR spectrum of 6 (Figure S1): the peak derived from the methylene of PEG appears at δ = 3.6 ppm, but that from the MeOTr group disappears at approximately 7 ppm.…”

Section: Resultsmentioning

confidence: 99%

“…13 C resonances were assigned with reference to a previously reported combination of heteronuclear single quantum correlation (HSQC) and 1 H-detected multiple bond coherence (HMBC) spectra. 26 SEC analysis was conducted with a Shodex GPC-101 system (Showa Denko K.K., Tokyo, Japan) equipped with a KF-G (Shodex) guard column, two KF-806 (Shodex) columns, and an RI-101 differential refractometer (Shodex) at a flow rate of 0.8 mL•min⁻ 1 at 40 °C. The eluent was tetrahydrofuran (THF), and the system was calibrated using standard samples of poly(methyl methacrylate) (PMMA).…”

Section: Measurementsmentioning

confidence: 99%

“…previously 26 and slightly modified in this study. Commercial chemicals were of the highest grade available and used without further purification.…”

Section: Synthesismentioning

confidence: 99%

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Conformational characteristics of regioselectively PEG/PS-grafted cellulosic bottlebrushes in solution: cross-sectional structure and main-chain stiffness

Kinose

Sakakibara

Tsujii

2022

Polym J

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Cellulosic bottlebrushes with polystyrene (PS) and poly(ethylene glycol) (PEG) side chains at the O-6 and O-2,3 positions, respectively (PEG-PS-cellulose), were synthesized and characterized in diluted solution to reveal the second structure of heterografted bottlebrushes. The regioselectivity and degree of substitution were evaluated by 1 H-and 13 C-nuclear magnetic resonance spectroscopy and size-exclusion chromatography (SEC). The cross-sectional structure of PEG-PS-cellulose was evaluated from the cross-sectional radius of gyration determined by the small angle X-ray scattering technique as a function of the molecular weight of the PS side chain. As a result, PEG-PS-cellulose was found to show a core-shell-corona structure, in which PEG and PS side chains formed a homogeneous shell layer surrounding the cellulosic core and the longer PS chains formed an outer corona layer. The stiffness parameter (λ -1 ) of the main chain was analyzed by the SEC-multiangle light scattering technique along with the Kratky-Porod wormlike chain model. In comparison with a previously reported cellulosic bottlebrush with a PS side chain at the O-6 position, it is suggested that the observed increase in λ -1 with increasing molecular weight of PS is mainly derived from the interaction among PS side chains located in an outer layer, while the PEG side chains at the O-2,3 position effectively suppressed the internal rotation of the cellulosic main chain.

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Section: Resultsmentioning

confidence: 99%

Section: Measurementsmentioning

confidence: 99%

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Conformational characteristics of regioselectively PEG/PS-grafted cellulosic bottlebrushes in solution: cross-sectional structure and main-chain stiffness

Kinose

Sakakibara

Tsujii

2022

Polym J

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“…The trityl group has been applied for the preparation of "cellulosic bottlebrushes". In this context, the 6-O-protected cellulose was allowed to react with 2-bromoisobutyryl bromide (Sakakibara et al 2018). The DS values of up to 0.90 could be realized.…”

Section: 3-o-functionalized Polysaccharide Derivativesmentioning

confidence: 99%

Structure design of polysaccharides by selective conversion: Old hat or topical?

Koschella

Heinze

2023

BioRes

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The functionalization pattern in polysaccharide derivatives is an important factor that determines their properties and, thus, their functions in applications. Regioselectively functionalized polysaccharide derivatives are used in material science because they may form lamellar structures in microscale by self-assembling. Intrinsically chiral polysaccharide derivatives are used for the separation of enantiomers by chromatography, and the separation efficiency is influenced by the regioselective distribution of substituents attached. Due to the multi-functionality of polysaccharides, their derivatization reactions usually yield products with random distribution of substituents. Thus, establishment of unambiguous structure-property relationships cannot be achieved. This review article summarizes recent developments in this topic. In addition to the blocking group techniques, synthesis methods applying activating substituents will be summarized. Moreover, the reaction medium itself may direct the substituent in a certain position without laborious multistep reactions.

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Regioselective synthesis of cellulosic janus bottlebrushes with polystyrene and poly (ε-caprolactone) side chains and their solid-state microphase separation

et al. 2021

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Synthesis of Cellulosic Bottlebrushes with Regioselectively Substituted Side Chains and Their Self‐assembly

Cited by 3 publications

References 28 publications

Conformational characteristics of regioselectively PEG/PS-grafted cellulosic bottlebrushes in solution: cross-sectional structure and main-chain stiffness

Conformational characteristics of regioselectively PEG/PS-grafted cellulosic bottlebrushes in solution: cross-sectional structure and main-chain stiffness

Structure design of polysaccharides by selective conversion: Old hat or topical?

Regioselective synthesis of cellulosic janus bottlebrushes with polystyrene and poly (ε-caprolactone) side chains and their solid-state microphase separation

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