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Akira Hirao - One of the best experts on this subject based on the ideXlab platform.
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Precise syntheses of structurally possible all tetrablock quaterpolymers by a methodology combining Living Anionic Polymerization with linking chemistry using 1 : 1 addition reaction
Polymer Chemistry, 2018Co-Authors: Raita Goseki, Yuri Matsuo, Akira HiraoAbstract:A methodology combining Living Anionic Polymerization with linking chemistry using 1 : 1 addition reaction has been developed for the syntheses of tetrablock quaterpolymers composed of A, B, C, and D blocks. With this methodology using the ω-chain-end-(α-phenylacrylate (PA))-functionalized D, α,ω-chain-end-(2-tetrahydropyranyl ether and PA)-functionalized D, and ω-chain-end-PA-functionalized AD as the building blocks, the following all structurally possible twelve tetrablock quaterpolymers were successfully synthesized: ABCD, ABDC, ACBD, ACDB, ADBC, ADCB, BACD, BADC, BCAD, BDAC, CABD, and CBAD. Polystyrene, poly(2-vinylpyridine), poly(tert-butyl methacrylate) (or poly(methyl methacrylate)), and poly(1,2-butylene oxide) prepared by Living Anionic Polymerization were used as A, B, C, and D blocks, respectively. The polymers synthesized in this study are quite new tetrablock quaterpolymers and well-defined in structure.
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Living Anionic Polymerization of 1,4-divinylbenzene and its derivatives
Reactive and Functional Polymers, 2018Co-Authors: Raita Goseki, Takashi Ishizone, Shunsuke Tanaka, Akira HiraoAbstract:Abstract The Living Anionic Polymerization of 1,4-divinylbenzene and its derivatives was reviewed. With the use of a specially-designed initiator system prepared from oligo(α-methylstyryl) lithium and potassium tert-butoxide, the Living Anionic Polymerization of 1,4-divinylbenzene was successfully realized for the first time. During this Polymerization, one of the two vinyl groups was selectively polymerized in a Living manner, while the other vinyl group remained completely intact in the main chain. Soluble linear polymers with well-controlled molecular weights up to 60.5 kg mol−1 and narrow molecular weight distributions (Mw/Mn
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Precise Synthesis of Macromolecular Architectures by Novel Iterative Methodology Combining Living Anionic Polymerization with Specially Designed Linking Chemistry.
Polymers, 2017Co-Authors: Raita Goseki, Yuri Matsuo, Tomoya Higashihara, Shotaro Ito, Akira HiraoAbstract:This article reviews the development of a novel all-around iterative methodology combining Living Anionic Polymerization with specially designed linking chemistry for macromolecular architecture syntheses. The methodology is designed in such a way that the same reaction site is always regenerated after the polymer chain is introduced in each reaction sequence, and this “polymer chain introduction and regeneration of the same reaction site” sequence is repeatable. Accordingly, the polymer chain can be successively and, in principle, limitlessly introduced to construct macromolecular architectures. With this iterative methodology, a variety of synthetically difficult macromolecular architectures, i.e., multicomponent μ-star polymers, high generation dendrimer-like hyperbranched polymers, exactly defined graft polymers, and multiblock polymers having more than three blocks, were successfully synthesized.
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tailored synthesis of triblock co and terpolymers composed of synthetically difficult sequence orders by combining Living Anionic Polymerization with specially designed linking reaction
Macromolecular Chemistry and Physics, 2016Co-Authors: Yuri Matsuo, Ryuji Konno, Takashi Ishizone, Raita Goseki, Akira HiraoAbstract:This study demonstrates the versatility and wider applicability of the recently developed methodology combining the Living Anionic Polymerization with a specially designed linking reaction using the α-phenylacrylate (or benzyl bromide) function, allowing the synthesis of triblock co- and terpolymers, which are otherwise difficut to be obtained by sequential addition of monomers during a sequential Polymerization approach. With this methodology using styrene and four para-substituted styrene derivatives with N-cyclohexylimine, 4-N,N-dimethyl-2-oxazoline, 2,6-di(tert-butyl)-4-methylphenyl ester, and nitrile, 12 polymers among the 16 possible triblock terpolymers and 6 triblock copolymers were successfully synthesized. Furthermore, the synthesis of two tetrablock quarterpolymers was achieved by the same linking methodology. The polymers synthesized in this study are all well-controlled in chain length, composition, which are difficult to be obtained by the sequential Polymerization. In addition, they possess functional groups usable for the further modification and introduction of other functionalities.
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Synthesis of well-controlled graft polymers by Living Anionic Polymerization towards exact graft polymers
Polymer Chemistry, 2014Co-Authors: Shotaro Ito, Takashi Ishizone, Raita Goseki, Akira HiraoAbstract:This article reviews the synthesis of well-controlled graft polymers by Living Anionic Polymerization towards exact graft polymers. The structure of a graft polymer is defined by the following three parameters: (1) molecular weight of the main chain, (2) molecular weight of the graft chain, and (3) placement of the graft chain. Based on these three parameters, the extent of the structural control of the graft polymers synthesized so far is described. Finally, the recently synthesized exact graft (co)polymers by stepwise iterative methodologies are introduced. In their structures, the three parameters are perfectly controlled.
M Beiner - One of the best experts on this subject based on the ideXlab platform.
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high temperature thermoplastic elastomers synthesized by Living Anionic Polymerization in hydrocarbon solvent at room temperature
Macromolecules, 2016Co-Authors: Weiyu Wang, Ralf Schlegel, Benjamin T White, Katherine Williams, Dimitry Voyloy, Carlos Alberto Steren, Andrew Goodwin, Bryan E Coughlin, Samuel P Gido, M BeinerAbstract:We present the synthesis and characterization of a new class of high temperature thermoplastic elastomers composed of polybenzofulvene–polyisoprene–polybenzofulvene (FIF) triblock copolymers. All copolymers were prepared by Living Anionic Polymerization in benzene at room temperature. HomoPolymerization and effects of additives on the glass transition temperature (Tg) of polybenzofulvene (PBF) were also investigated. Among all triblock copolymers studied, FIF with 14 vol % of PBF exhibited a maximum stress of 14.3 ± 1.3 MPa and strain at break of 1390 ± 66% from tensile tests. The stress–strain curves of FIF-10 and 14 were analyzed by a statistical molecular approach using a nonaffine tube model to estimate the thermoplastic elastomer behavior. Dynamic mechanical analysis showed that the softening temperature of PBF in FIF was 145 °C, much higher than that of thermoplastic elastomers with polystyrene hard blocks. Microphase separation of FIF triblock copolymers was observed by small-angle X-ray scattering...
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High Temperature Thermoplastic Elastomers Synthesized by Living Anionic Polymerization in Hydrocarbon Solvent at Room Temperature
2016Co-Authors: Weiyu Wang, Ralf Schlegel, Katherine Williams, Dimitry Voyloy, Carlos Alberto Steren, Andrew Goodwin, Bryan E Coughlin, Samuel P Gido, Benjamin T. White, M BeinerAbstract:We present the synthesis and characterization of a new class of high temperature thermoplastic elastomers composed of polybenzofulvene–polyisoprene–polybenzofulvene (FIF) triblock copolymers. All copolymers were prepared by Living Anionic Polymerization in benzene at room temperature. HomoPolymerization and effects of additives on the glass transition temperature (Tg) of polybenzofulvene (PBF) were also investigated. Among all triblock copolymers studied, FIF with 14 vol % of PBF exhibited a maximum stress of 14.3 ± 1.3 MPa and strain at break of 1390 ± 66% from tensile tests. The stress–strain curves of FIF-10 and 14 were analyzed by a statistical molecular approach using a nonaffine tube model to estimate the thermoplastic elastomer behavior. Dynamic mechanical analysis showed that the softening temperature of PBF in FIF was 145 °C, much higher than that of thermoplastic elastomers with polystyrene hard blocks. Microphase separation of FIF triblock copolymers was observed by small-angle X-ray scattering, even though long-range order was not achieved under the annealing conditions employed. In addition, the microphase separation of the resulting triblock copolymers was examined by atomic force microscopy
Weiyu Wang - One of the best experts on this subject based on the ideXlab platform.
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high temperature thermoplastic elastomers synthesized by Living Anionic Polymerization in hydrocarbon solvent at room temperature
Macromolecules, 2016Co-Authors: Weiyu Wang, Ralf Schlegel, Benjamin T White, Katherine Williams, Dimitry Voyloy, Carlos Alberto Steren, Andrew Goodwin, Bryan E Coughlin, Samuel P Gido, M BeinerAbstract:We present the synthesis and characterization of a new class of high temperature thermoplastic elastomers composed of polybenzofulvene–polyisoprene–polybenzofulvene (FIF) triblock copolymers. All copolymers were prepared by Living Anionic Polymerization in benzene at room temperature. HomoPolymerization and effects of additives on the glass transition temperature (Tg) of polybenzofulvene (PBF) were also investigated. Among all triblock copolymers studied, FIF with 14 vol % of PBF exhibited a maximum stress of 14.3 ± 1.3 MPa and strain at break of 1390 ± 66% from tensile tests. The stress–strain curves of FIF-10 and 14 were analyzed by a statistical molecular approach using a nonaffine tube model to estimate the thermoplastic elastomer behavior. Dynamic mechanical analysis showed that the softening temperature of PBF in FIF was 145 °C, much higher than that of thermoplastic elastomers with polystyrene hard blocks. Microphase separation of FIF triblock copolymers was observed by small-angle X-ray scattering...
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High Temperature Thermoplastic Elastomers Synthesized by Living Anionic Polymerization in Hydrocarbon Solvent at Room Temperature
2016Co-Authors: Weiyu Wang, Ralf Schlegel, Katherine Williams, Dimitry Voyloy, Carlos Alberto Steren, Andrew Goodwin, Bryan E Coughlin, Samuel P Gido, Benjamin T. White, M BeinerAbstract:We present the synthesis and characterization of a new class of high temperature thermoplastic elastomers composed of polybenzofulvene–polyisoprene–polybenzofulvene (FIF) triblock copolymers. All copolymers were prepared by Living Anionic Polymerization in benzene at room temperature. HomoPolymerization and effects of additives on the glass transition temperature (Tg) of polybenzofulvene (PBF) were also investigated. Among all triblock copolymers studied, FIF with 14 vol % of PBF exhibited a maximum stress of 14.3 ± 1.3 MPa and strain at break of 1390 ± 66% from tensile tests. The stress–strain curves of FIF-10 and 14 were analyzed by a statistical molecular approach using a nonaffine tube model to estimate the thermoplastic elastomer behavior. Dynamic mechanical analysis showed that the softening temperature of PBF in FIF was 145 °C, much higher than that of thermoplastic elastomers with polystyrene hard blocks. Microphase separation of FIF triblock copolymers was observed by small-angle X-ray scattering, even though long-range order was not achieved under the annealing conditions employed. In addition, the microphase separation of the resulting triblock copolymers was examined by atomic force microscopy
Raita Goseki - One of the best experts on this subject based on the ideXlab platform.
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Living Anionic Polymerization of 1,4-divinylbenzene and its derivatives
Reactive and Functional Polymers, 2018Co-Authors: Raita Goseki, Takashi Ishizone, Shunsuke Tanaka, Akira HiraoAbstract:Abstract The Living Anionic Polymerization of 1,4-divinylbenzene and its derivatives was reviewed. With the use of a specially-designed initiator system prepared from oligo(α-methylstyryl) lithium and potassium tert-butoxide, the Living Anionic Polymerization of 1,4-divinylbenzene was successfully realized for the first time. During this Polymerization, one of the two vinyl groups was selectively polymerized in a Living manner, while the other vinyl group remained completely intact in the main chain. Soluble linear polymers with well-controlled molecular weights up to 60.5 kg mol−1 and narrow molecular weight distributions (Mw/Mn
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Precise syntheses of structurally possible all tetrablock quaterpolymers by a methodology combining Living Anionic Polymerization with linking chemistry using 1 : 1 addition reaction
Polymer Chemistry, 2018Co-Authors: Raita Goseki, Yuri Matsuo, Akira HiraoAbstract:A methodology combining Living Anionic Polymerization with linking chemistry using 1 : 1 addition reaction has been developed for the syntheses of tetrablock quaterpolymers composed of A, B, C, and D blocks. With this methodology using the ω-chain-end-(α-phenylacrylate (PA))-functionalized D, α,ω-chain-end-(2-tetrahydropyranyl ether and PA)-functionalized D, and ω-chain-end-PA-functionalized AD as the building blocks, the following all structurally possible twelve tetrablock quaterpolymers were successfully synthesized: ABCD, ABDC, ACBD, ACDB, ADBC, ADCB, BACD, BADC, BCAD, BDAC, CABD, and CBAD. Polystyrene, poly(2-vinylpyridine), poly(tert-butyl methacrylate) (or poly(methyl methacrylate)), and poly(1,2-butylene oxide) prepared by Living Anionic Polymerization were used as A, B, C, and D blocks, respectively. The polymers synthesized in this study are quite new tetrablock quaterpolymers and well-defined in structure.
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Precise Synthesis of Macromolecular Architectures by Novel Iterative Methodology Combining Living Anionic Polymerization with Specially Designed Linking Chemistry.
Polymers, 2017Co-Authors: Raita Goseki, Yuri Matsuo, Tomoya Higashihara, Shotaro Ito, Akira HiraoAbstract:This article reviews the development of a novel all-around iterative methodology combining Living Anionic Polymerization with specially designed linking chemistry for macromolecular architecture syntheses. The methodology is designed in such a way that the same reaction site is always regenerated after the polymer chain is introduced in each reaction sequence, and this “polymer chain introduction and regeneration of the same reaction site” sequence is repeatable. Accordingly, the polymer chain can be successively and, in principle, limitlessly introduced to construct macromolecular architectures. With this iterative methodology, a variety of synthetically difficult macromolecular architectures, i.e., multicomponent μ-star polymers, high generation dendrimer-like hyperbranched polymers, exactly defined graft polymers, and multiblock polymers having more than three blocks, were successfully synthesized.
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tailored synthesis of triblock co and terpolymers composed of synthetically difficult sequence orders by combining Living Anionic Polymerization with specially designed linking reaction
Macromolecular Chemistry and Physics, 2016Co-Authors: Yuri Matsuo, Ryuji Konno, Takashi Ishizone, Raita Goseki, Akira HiraoAbstract:This study demonstrates the versatility and wider applicability of the recently developed methodology combining the Living Anionic Polymerization with a specially designed linking reaction using the α-phenylacrylate (or benzyl bromide) function, allowing the synthesis of triblock co- and terpolymers, which are otherwise difficut to be obtained by sequential addition of monomers during a sequential Polymerization approach. With this methodology using styrene and four para-substituted styrene derivatives with N-cyclohexylimine, 4-N,N-dimethyl-2-oxazoline, 2,6-di(tert-butyl)-4-methylphenyl ester, and nitrile, 12 polymers among the 16 possible triblock terpolymers and 6 triblock copolymers were successfully synthesized. Furthermore, the synthesis of two tetrablock quarterpolymers was achieved by the same linking methodology. The polymers synthesized in this study are all well-controlled in chain length, composition, which are difficult to be obtained by the sequential Polymerization. In addition, they possess functional groups usable for the further modification and introduction of other functionalities.
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Synthesis of well-controlled graft polymers by Living Anionic Polymerization towards exact graft polymers
Polymer Chemistry, 2014Co-Authors: Shotaro Ito, Takashi Ishizone, Raita Goseki, Akira HiraoAbstract:This article reviews the synthesis of well-controlled graft polymers by Living Anionic Polymerization towards exact graft polymers. The structure of a graft polymer is defined by the following three parameters: (1) molecular weight of the main chain, (2) molecular weight of the graft chain, and (3) placement of the graft chain. Based on these three parameters, the extent of the structural control of the graft polymers synthesized so far is described. Finally, the recently synthesized exact graft (co)polymers by stepwise iterative methodologies are introduced. In their structures, the three parameters are perfectly controlled.
Mark D. Foster - One of the best experts on this subject based on the ideXlab platform.
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Precision Synthesis of ω-Branch, End-Functionalized Comb Polystyrenes Using Living Anionic Polymerization and Thiol–Ene “Click” Chemistry
Macromolecules, 2012Co-Authors: Boxi Liu, Roderic P. Quirk, Chrys Wesdemiotis, Aleer M. Yol, Mark D. FosterAbstract:A combination of Living Anionic Polymerization and thiol–ene “click” chemistry provides an efficient and convenient method for synthesis of well-defined comb polystyrenes with precisely controlled architecture details and a wide selection of functionalities. ω-(p-Vinylbenzyl)polystyrene macromonomer was synthesized by sec-butyllithium-initiated Polymerization of styrene followed by termination with 4-vinylbenzyl chloride (VBC). For the synthesis of α-4-pentenyl-ω-(p-vinylbenzyl)polystyrene macromonomer, an unsaturated initiator, 4-pentenyllithium, was used followed by termination with VBC. To ensure successful Living Anionic Polymerization of macromonomers, impurities present in the macromonomers and glass reactors were readily removed by titration with excess sec-butyllithium initiator right before initiation, resulting in polymacromonomers with controlled Mn (74 000, 130 000 g/mol) and narrow Mw/Mn. Living Anionic coPolymerization of mixtures of both types of macromonomers yielded a well-defined comb-sh...
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precision synthesis of ω branch end functionalized comb polystyrenes using Living Anionic Polymerization and thiol ene click chemistry
Macromolecules, 2012Co-Authors: Boxi Liu, Roderic P. Quirk, Chrys Wesdemiotis, Aleer M. Yol, Mark D. FosterAbstract:A combination of Living Anionic Polymerization and thiol–ene “click” chemistry provides an efficient and convenient method for synthesis of well-defined comb polystyrenes with precisely controlled architecture details and a wide selection of functionalities. ω-(p-Vinylbenzyl)polystyrene macromonomer was synthesized by sec-butyllithium-initiated Polymerization of styrene followed by termination with 4-vinylbenzyl chloride (VBC). For the synthesis of α-4-pentenyl-ω-(p-vinylbenzyl)polystyrene macromonomer, an unsaturated initiator, 4-pentenyllithium, was used followed by termination with VBC. To ensure successful Living Anionic Polymerization of macromonomers, impurities present in the macromonomers and glass reactors were readily removed by titration with excess sec-butyllithium initiator right before initiation, resulting in polymacromonomers with controlled Mn (74 000, 130 000 g/mol) and narrow Mw/Mn. Living Anionic coPolymerization of mixtures of both types of macromonomers yielded a well-defined comb-sh...
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Synthesis of Cyclic Polystyrenes Using Living Anionic Polymerization and Metathesis Ring-Closure
Macromolecules, 2011Co-Authors: Roderic P. Quirk, Chrys Wesdemiotis, Mark D. Foster, Shih-fan Wang, Aleer M. YolAbstract:A combination of Living Anionic Polymerization and metathesis ring-closure provides an efficient method for synthesis of well-defined, macrocyclic polymers over a broad molecular weight range. A series of well-defined, α,ω-divinylpolystyrene precursors (Mn = 2800, 8600, 17000, and 38000 g/mol) were synthesized by 4-pentenyllithium-initiated Polymerization of styrene followed by termination with 4-chloromethylstyrene. Efficient cyclization of these α,ω-divinylpolystyrene precursors was effected in CH2Cl2 and CH2Cl2/cyclohexane mixtures using a Grubb’s catalyst, bis(tricyclohexylphosphine)benzylidine ruthenium(IV) chloride. As the precursor Mn increased, more cyclohexane was added and the concentration of the precursor was decreased from 1.41 × 10–4 to 2.15 × 10–6 M. The macrocyclic polymers were uniquely characterized by MALDI–TOF mass spectrometry in terms of peaks that appeared characteristically 28 m/z units lower than those of the corresponding open-chain precursor peaks, corresponding to the loss of a...