The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Akira Hirao - 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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Anionic Polymerization : principles, practice, strength, consequences and applications
2015Co-Authors: Nikos Hadjichristidis, Akira HiraoAbstract:Schlenk Techniques for Anionic Polymerization.- High Vacuum Techniques for Anionic Polymerization.- Non-Polar Monomers: Styrene and 1,3-Butadiene Derivatives.- Anionic Polymerization of Polar Vinyl Monomers: Vinylpyridines, (Meth)acrylates, (Meth)acrylamides, (Meth)acrylonitrile, Phenyl Vinyl Sulfoxide, Benzofulvene and Other Monomers.- Cyclic Monomers: Epoxides, Lactide, Lactones, Lactams, Cyclic Silicon-containing monomers, Cyclic Carbonates and others.- Ring-opening Polymerization of N-carboxyanhydrides for preparation of polypeptides and polypeptide-based hybrid materials with various molecular architectures.- Living Anionic Polymerization of Isocyanates.- Poly(ferrocenylsilanes) with controlled macromolecular architecture by Anionic Polymerization: Applications in patterning and lithography.- Polymerization Using Phosphazene Bases.- Group Transfer Polymerization of Acrylic Monomers.- Surface Initiated Anionic Polymerization from Nanomaterials.- Block Copolymers by Anionic Polymerization: Recent Synthetic Routes and Developments.- Graft and Comblike Polymers.- Star-Branched Polymers (Star Polymers).- Synthesis of Dendrimer-like Polymers.- Complex Branched Polymers.- Block Copolymers Containing Polythiophene Segments.- Block Copolymers and Miktoarm Star-Branched Polymers.- Control of Surface Structure and Dynamics of Polymers Based on Precision Synthesis.- Block Copolymers as Anti-fouling and Fouling Resistant Coatings.- Micellar Structures from Anionically Synthesized Block Copolymers.- Block Copolymers for Self-assembling Lithographic Materials.- Methacrylate-Based Polymers for Industrial Uses.- The Critical Role of Anionic Polymerization for Advances in the Physics of Polyolefins.- Future Remarks.
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Materials Science and Technology - Anionic Polymerization: Recent Advances
Materials Science and Technology, 2012Co-Authors: Takashi Ishizone, Akira HiraoAbstract:The sections in this article are Background Living Anionic Polymerization of Various Monomers Styrene Derivatives 1,3-Diene Monomers 2- and 4-Vinylpyridines (Meth)acrylate Derivatives Acrylamide Derivatives Cyclic Monomers Other Monomers Reaction of Living Anionic Polymers with Electrophiles: Synthesis of Chain-Functionalized Polymers Synthesis of Architectural Polymers via Living Anionic Polymerization Block Copolymers Graft Copolymers Star-Branched Polymers Complex Architectural Polymers Anionic Polymerization: Practical Aspects Concluding Remarks Keywords: Anionic Polymerization; living Anionic Polymerization; styrene; 1,3-butadiene; isoprene; alkyl (meth)acrylates; acrylamides; protective group; functional polymers; architectural polymers; block copolymers; star-branched polymers; dendrimer-like star-branched polymers; molecular weight control; narrow molecular weight distribution; stereoregularity; chain-functionalization
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Anionic Polymerization of Protected Functional Monomers
Polymer Science: A Comprehensive Reference, 2012Co-Authors: Takashi Ishizone, Kenji Sugiyama, Akira HiraoAbstract:This chapter reviews the living Anionic Polymerization of protected functional monomers. The functional monomers include styrenes, 1,3-butadienes, alkyl (meth)acrylates, and acrylamide derivatives. A variety of highly useful functional groups, which would normally participate in termination or chain transfer reactions in Anionic Polymerization, are masked by appropriate protective groups prior to Polymerization. The resulting protected functional monomers smoothly undergo Anionic Polymerizations to afford stable ‘living polymers’, similar to those obtained by corresponding nonfunctional monomers. After Polymerization, the protective groups are quantitatively removed to regenerate the original functional groups, yielding well-defined polymers having functional groups in all monomer units as well as precisely controlled molecular weights and narrow molecular weight distributions.
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living Anionic Polymerization of styrene derivatives para substituted with π conjugated oligo fluorene moieties
Macromolecules, 2009Co-Authors: Kenji Sugiyama, Akira Hirao, Jungching Hsu, Yichih Tung, Wenchang ChenAbstract:The Anionic Polymerization of styrene monomers para-substituted with π-conjugated mono-, di-, and tri(9,9-dihexylfluorene) moieties, St-Fl, St-Fl2, and St-Fl3, was examined under the conditions either in THF at −78 °C or in tert-butylbenzene at 20 °C with sec-BuLi as an initiator. The Polymerization of both St-Fl and St-Fl2 was found to proceed in a living manner to quantitatively afford the corresponding polymers with predictable molecular weights and narrow molecular weight distributions (Mw/Mn < 1.08). The Anionic Polymerization of St-Fl3 was also indicative to proceed in a living manner but with an unpredictable molecular weight. Both AB and BA diblock copolymers with the well-defined and expected structures could be successfully prepared by the sequential addition of St-Fl or St-Fl2 followed by styrene and vice versa. The block coPolymerization results clearly indicate the living nature of the Anionic Polymerization of St-Fl and St-Fl2 and the almost same Anionic Polymerization behaviors of both mono...
Jimmy W. Mays - One of the best experts on this subject based on the ideXlab platform.
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poly 1 adamantyl acrylate living Anionic Polymerization block coPolymerization and thermal properties
Macromolecules, 2016Co-Authors: Wei Lu, Nam-goo Kang, Kunlun Hong, Caili Huang, Jimmy W. MaysAbstract:Living Anionic Polymerization of acrylates is challenging due to intrinsic side reactions including backbiting reactions of propagating enolate anions and aggregation of active chain ends. In this study, the controlled synthesis of poly(1-adamatyl acrylate) (PAdA) was performed successfully for the first time via living Anionic Polymerization through investigation of the initiation systems of sec-butyllithium/diphenylethylene/lithium chloride (sec-BuLi/DPE/LiCl), diphenylmethylpotassium/diethylzinc (DPMK/Et2Zn), and sodium naphthalenide/dipenylethylene/diethylzinc (Na-Naph/DPE/Et2Zn) in tetrahydrofuran at −78 °C using custom glass-blowing and high-vacuum techniques. PAdA synthesized via Anionic Polymerization using DPMK with a large excess (more than 40-fold to DPMK) of Et2Zn as the ligand exhibited predicted molecular weights from 4.3 to 71.8 kg/mol and polydispersity indices of around 1.10. In addition, the produced PAdAs exhibit a low level of isotactic content (mm triads of 2.1%). The block copolymers...
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Poly(1-adamantyl acrylate): Living Anionic Polymerization, Block CoPolymerization, and Thermal Properties
2016Co-Authors: Caili Huang, Nam-goo Kang, Kunlun Hong, Jimmy W. MaysAbstract:Living Anionic Polymerization of acrylates is challenging due to intrinsic side reactions including backbiting reactions of propagating enolate anions and aggregation of active chain ends. In this study, the controlled synthesis of poly(1-adamatyl acrylate) (PAdA) was performed successfully for the first time via living Anionic Polymerization through investigation of the initiation systems of sec-butyllithium/diphenylethylene/lithium chloride (sec-BuLi/DPE/LiCl), diphenylmethylpotassium/diethylzinc (DPMK/Et2Zn), and sodium naphthalenide/dipenylethylene/diethylzinc (Na-Naph/DPE/Et2Zn) in tetrahydrofuran at −78 °C using custom glass-blowing and high-vacuum techniques. PAdA synthesized via Anionic Polymerization using DPMK with a large excess (more than 40-fold to DPMK) of Et2Zn as the ligand exhibited predicted molecular weights from 4.3 to 71.8 kg/mol and polydispersity indices of around 1.10. In addition, the produced PAdAs exhibit a low level of isotactic content (mm triads of 2.1%). The block copolymers of AdA and methyl methacrylate (MMA) were obtained by sequential Anionic Polymerization, and the distinct living property of PAdA over other acrylates was demonstrated based on the observation that the resulting PAdA-b-PMMA block copolymers were formed with no residual PAdA homopolymer. The PAdA homopolymers exhibit a very high glass transition temperature (133 °C) and outstanding thermal stability (Td: 376 °C) as compared to other acrylic polymers such as poly(tert-butyl acrylate) and poly(methyl acrylate). These merits make PAdA a promising candidate for acrylic-based thermoplastic elastomers with high upper service temperature and enhanced mechanical strength
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High Vacuum Techniques for Anionic Polymerization
Anionic Polymerization, 2015Co-Authors: Kedar Ratkanthwar, Nikolaos Hadjichristidis, Jimmy W. MaysAbstract:Anionic Polymerization high vacuum techniques (HVTs) are the most suitable for the preparation of polymer samples with well-defined complex macromolecular architectures. Though HVTs require glassblowing skill for designing and making Polymerization reactor, it is the best way to avoid any termination of living polymers during the number of steps for the synthesis of polymers with complex structure. In this chapter, we describe the different Polymerization reactors and HVTs for the purification of monomers, solvents, and other reagents for Anionic Polymerization as well as few model reactions for the synthesis of polymers with simple to complex structure.
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Schlenk Techniques for Anionic Polymerization
Anionic Polymerization, 2015Co-Authors: Kedar Ratkanthwar, Nikolaos Hadjichristidis, Junpeng Zhao, Hefeng Zhang, Jimmy W. MaysAbstract:Anionic Polymerization-high vacuum techniques (HVTs) are doubtlessly the most prominent and reliable experimental tools to prepare polymer samples with well-defined and, in many cases, complex macromolecular architectures. Due to the high demands for time and skilled technical personnel, HVTs are currently used in only a few research laboratories worldwide. Instead, most researchers in this filed are attracted to more facile Schlenk techniques. The basic principle of this technique followed in all laboratories is substantially the same, i.e. the use of alternate vacuum and inert gas atmosphere in glass apparatus for the purification/charging of monomer, solvents, additives, and for the manipulation of air-sensitive compounds such as alkyl metal initiators, organometallic or organic catalysts. However, it is executed quite differently in each research group in terms of the structure of Schlenk apparatus (manifolds, connections, purification/storage flasks, reactors, etc.), the use of small supplementary devices (soft tubing, cannulas, stopcocks, etc.) and experimental procedures. The operational methods are partly purpose-oriented while also featured by a high flexibility, which makes it impossible to describe in detail each specific one. In this chapter we will briefly exemplify the application of Schlenk techniques for Anionic Polymerization by describing the performance of a few experiments from our own work.
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Experimental techniques in high‐vacuum Anionic Polymerization
Journal of Polymer Science Part A: Polymer Chemistry, 2005Co-Authors: David Uhrig, Jimmy W. MaysAbstract:Experimental methods used in high-vacuum Anionic Polymerization are described in detail, with extensive illustrations to demonstrate proper procedures and techniques. These descriptions include construction and operation of the vacuum line, handling purification chemicals, ampulization techniques, short-path distillations, initiator synthesis, Polymerization procedures, and linking reactions using chlorosilanes. A primary emphasis is placed on safety. We believe that this review of these methods will be useful to scientists working in the field of Anionic Polymerization and may also benefit other researchers in performing tasks requiring ultra-high-purity reaction conditions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6179–6222, 2005
Takashi Ishizone - 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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Materials Science and Technology - Anionic Polymerization: Recent Advances
Materials Science and Technology, 2012Co-Authors: Takashi Ishizone, Akira HiraoAbstract:The sections in this article are Background Living Anionic Polymerization of Various Monomers Styrene Derivatives 1,3-Diene Monomers 2- and 4-Vinylpyridines (Meth)acrylate Derivatives Acrylamide Derivatives Cyclic Monomers Other Monomers Reaction of Living Anionic Polymers with Electrophiles: Synthesis of Chain-Functionalized Polymers Synthesis of Architectural Polymers via Living Anionic Polymerization Block Copolymers Graft Copolymers Star-Branched Polymers Complex Architectural Polymers Anionic Polymerization: Practical Aspects Concluding Remarks Keywords: Anionic Polymerization; living Anionic Polymerization; styrene; 1,3-butadiene; isoprene; alkyl (meth)acrylates; acrylamides; protective group; functional polymers; architectural polymers; block copolymers; star-branched polymers; dendrimer-like star-branched polymers; molecular weight control; narrow molecular weight distribution; stereoregularity; chain-functionalization
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Anionic Polymerization of Protected Functional Monomers
Polymer Science: A Comprehensive Reference, 2012Co-Authors: Takashi Ishizone, Kenji Sugiyama, Akira HiraoAbstract:This chapter reviews the living Anionic Polymerization of protected functional monomers. The functional monomers include styrenes, 1,3-butadienes, alkyl (meth)acrylates, and acrylamide derivatives. A variety of highly useful functional groups, which would normally participate in termination or chain transfer reactions in Anionic Polymerization, are masked by appropriate protective groups prior to Polymerization. The resulting protected functional monomers smoothly undergo Anionic Polymerizations to afford stable ‘living polymers’, similar to those obtained by corresponding nonfunctional monomers. After Polymerization, the protective groups are quantitatively removed to regenerate the original functional groups, yielding well-defined polymers having functional groups in all monomer units as well as precisely controlled molecular weights and narrow molecular weight distributions.
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living Anionic Polymerization of n methacryloylazetidine Anionic polymerizability of n n dialkylmethacrylamides
Macromolecules, 2010Co-Authors: Takashi Suzuki, Junichi Kusakabe, Keita Kitazawa, Takeshi Nakagawa, Susumu Kawauchi, Takashi IshizoneAbstract:Anionic Polymerization of a series of N,N-dialkylmethacrylamides such as N-methacryloylazetidine (M4), N-methacryloylpyrrolidine (M5), and N-methacryloylpiperidine (M6) was carried out with diphenylmethyllithium (Ph2CHLi) or diphenylmethylpotassium (Ph2CHK) in the presence of LiCl or Et2Zn in THF to clarify the relationship between polymerizability and monomer structure. Poly(M4)s possessing predicted molecular weights and very narrow molecular weight distributions (Mw/Mn < 1.1) were obtained quantitatively with Ph2CHLi/LiCl or Ph2CHK/Et2Zn at −40 to 0 °C within 24 h. From the Polymerizations of M4 at the various temperatures ranging from −40 to −20 °C, the apparent rate constant and the activation energy of the Anionic Polymerization were determined as follows: ln kpap = −6.17 × 103/T + 22.4 L mol−1 s−1 and 51 ± 5 kJ mol−1, respectively. Compared to the previous report on the Anionic Polymerization of N-methacryloyl-2-methylaziridine (M3), the Polymerization rate of M4 was significantly slower and the ac...
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Recent advance in living Anionic Polymerization of functionalized styrene derivatives
Progress in Polymer Science, 2002Co-Authors: Akira Hirao, Surapich Loykulnant, Takashi IshizoneAbstract:Abstract This review covers recent advance of living Anionic Polymerization of styrene derivatives with functional groups. Although there have so far been reported several successful systems of living Anionic Polymerization of functionalized styrene derivatives, most useful functional groups are not amenable to the conditions of living Anionic Polymerization of styrene. Therefore, we herein present two generalized strategies to be able to achieve the living Anionic Polymerization of styrenes with such functional groups that are normally incompatible with carbAnionic species. The first strategy involves protection of the functional group and living Anionic Polymerization of the resulting protected monomer, followed by deprotection to regenerate the original functional group after the Polymerization. In the second strategy, an electron-withdrawing functional group is introduced into the benzene ring of styrene to purposefully lower the reactivity of the generated chain-end carbanion, thereby allowing the functional group and the carbanion to coexist. The living Anionic Polymerization of a number of styrene derivatives with functional groups became indeed possible by employing two proposed strategies. Their scopes, limitations, and possibilities are also discussed.
Robert Jérôme - One of the best experts on this subject based on the ideXlab platform.
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Materials Science and Technology - Anionic Polymerization: Recent Advances
Materials Science and Technology, 2013Co-Authors: Robert Jérôme, Philippe TeyssieAbstract:The sections in this article are Introduction General Aspects of Anionic Living Polymerization Strategies Group Transfer Polymerization A Discussed Mechanism A Remarkable Macromolecular Architecture Metal-Free Anionic Polymerization Nucleophilic/Coordinative Polymerization Organolanthanides (III)-Initiated Polymerization Metalloporphyrin-Mediated Nucleophilic Polymerizations “Ligated” Anionic Polymerization Ion-Pairs Complexation: Nature of Ligands Effect of Ligands on Thermodynamics Coordination Strength of σ-Chelating Ligands Steric Hindrance around the “Ligated” Ion-Pairs Effect of Ligands on Kinetics Modification of the Association Equilibria Modification of the Solvation Equilibria A Golden Tool for Macromolecular Engineering Conclusions
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Recent achievements in Anionic Polymerization of (meth)acrylates
Journal of Polymer Science Part A: Polymer Chemistry, 1999Co-Authors: Robert Jérôme, Philippe Teyssie, Bruno Vuillemin, Thomas Zundel, Catherine ZuneAbstract:The constant progress of the Anionic Polymerization of (meth)acrylates is discussed from both the fundamental and practical points of view. A special attention is paid to the improved macromolecular engineering of (meth)acrylate-based (co)polymers. The resulting most important materials and the scaling-up process needed for their production are also emphasized. The recent developments witness for the healthy state of the Anionic Polymerization of these polar monomers. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1–10, 1999
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Anionic Polymerization of (meth)acrylic monomers: Anionic Polymerization of tert-butyl methacrylate in toluene
Polymer International, 1999Co-Authors: Catherine Zune, Philippe Dubois, Robert JérômeAbstract:The Anionic Polymerization of tBMA initiated by an organolithium compound in toluene at low temperature (−78 °C and 0 °C) has been revisited. Under these experimental conditions, no ‘livingness’ is reported, consistently with formation of an important fraction of oligomers (Mn = 650). © 1999 Society of Chemical Industry
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Anionic Polymerization of methacrylic monomers: characterization of the propagating species
Progress in Polymer Science, 1999Co-Authors: Catherine Zune, Robert JérômeAbstract:Abstract Ligation of the Anionic species responsible for the Polymerization (LAP) of alkyl(meth)acrylates has much contributed to improve Polymerization control. This ligated Anionic Polymerization has been firstly studied by using model compounds, such as low molecular weight lithium ester enolates. Recently, effort has been devoted to the direct analysis of the species that propagate the Anionic Polymerization of (meth)acrylates. In addition to IR, multinuclear NMR spectroscopy has been very instrumental in the elucidation of the structure and aggregation of the active species and how these characteristic features are modified by the addition of various types of ligands. This substantial progress in the characterization of the polyalkyl(meth)acrylate anions, ligated or not, is reported in this review.
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Recent developments in Anionic Polymerization
Current Opinion in Solid State and Materials Science, 1998Co-Authors: Robert Jérôme, Jiang-dong TongAbstract:Abstract The past year witnessed very significant advances in the living Anionic Polymerization of (meth)acrylate monomers, particularly in hydrocarbons at or below 0°C. Block Polymerization of alkyl methacrylates with primary alkyl acrylates, although somewhat improved, remains a challenge. Anionic Polymerization of styrene, diene and its derivatives was carried out with the aim of synthesizing functional polymers and block copolymers of various architectures. There has been a trend towards combining different living techniques in order to design polymers of unique architectures and properties
Itaru Natori - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of functionalized fullerene-C60 by the living Anionic Polymerization technique
Journal of Applied Polymer Science, 2010Co-Authors: Itaru Natori, Shizue Natori, Yuto HiroseAbstract:The synthesis of functionalized fullerene-C 60 (C 60 ) was performed using living Anionic Polymerization. The metalation of the benzylic hydrogen atom on toluene or p-substituted toluene was conducted with the alkyllithium/amine system, and examined by living Anionic Polymerization of 1,3-cyclohexadiene. The number of carbanions bonded onto C 60 was estimated by the grafting reaction of living polymer onto C 60 . The tert-butyllithium/ N,N,N',N'-tetramethylethylenediamine system was an effective metalation reagent, and toluene-, p-xylene-, 4-methyltriphenylamine-functionalized C 60 s having good solubility were successfully synthesized.
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Anionic Polymerization of 9-vinylanthracene with the alkyllithium/amine system
Polymers for Advanced Technologies, 2009Co-Authors: Itaru Natori, Shizue NatoriAbstract:The Anionic Polymerization of 9-vinylanthracene (VAN) with the alkyllithium (RLi)/amine system was examined to explore new initiator systems that could polymerize VAN at moderate temperatures in hydrocarbon solvents. Important factors in the Anionic Polymerization of VAN were found to be the high nucleophilicity of the RLi/amine and poly(9-vinylanthracenyl)lithium (PVANLi)/amine systems, the low steric hindrance of the amine molecule, and good solubility of PVANLi during the Polymerization. The t-butyllithium (t-BuLi)/N,N,N',N'-tetramethylethylenediamine (TMEDA) (1.00/1.25) system achieved the highest PVAN yield in toluene at room temperature (ca. 25°C), although the limitations of yield and the number average molecular weight (Mn) were around 90 wt% and 2000, respectively. The results obtained from spectrum analyses suggested that the Anionically polymerized PVAN would be considered a favorable polymer for the preparation of new luminescent materials. Copyright © 2009 John Wiley & Sons, Ltd.
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Anionic Polymerization of 4 diphenylaminostyrene characteristics of the alkyllithium n n n n tetramethylethylenediamine system for living Anionic Polymerization
Macromolecules, 2008Co-Authors: Itaru Natori, Shizue Natori, Hiroaki Usui, Hisaya SatoAbstract:A well-controlled Anionic Polymerization of 4-diphenylaminostyrene (DAS) with alkyllithium (RLi) has been achieved for the first time. The nucleophilicity and solubility of RLi, 4-diphenylaminostyryllithium (DASLi), and poly(4-diphenylaminostyryl)lithium (PDASLi) were very important controlling factors. An initiator system of tert-butyllithium (t-BuLi)/N,N,N′,N′-tetramethylethylenediamine (TMEDA) in toluene was found to be very effective. In this system, the t-BuLi/TMEDA complex reacts with toluene to form the benzyllithium (BzLi)/TMEDA complex, and this complex initiates the Anionic Polymerization of DAS. The DASLi/TMEDA and PDASLi/TMEDA complexes have sufficient nucleophilicity and stability as propagating species, without the metalation of toluene, and as a result, living Anionic Polymerization was achieved. The high molecular weight poly(4-diphenylaminostyrene) (PDAS), synthesized using the RLi/TMEDA system, had a syndiotactic-rich configuration, independent of the Polymerization solvent.
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Anionic Polymerization of 4-Diphenylaminostyrene : Characteristics of the Alkyllithium/N,N,N',N'-Tetramethylethylenediamine System for Living Anionic Polymerization
Macromolecules, 2008Co-Authors: Itaru Natori, Shizue Natori, Hiroaki Usui, Hisaya SatoAbstract:A well-controlled Anionic Polymerization of 4-diphenylaminostyrene (DAS) with alkyllithium (RLi) has been achieved for the first time. The nucleophilicity and solubility of RLi, 4-diphenylaminostyryllithium (DASLi), and poly(4-diphenylaminostyryl)lithium (PDASLi) were very important controlling factors. An initiator system of tert-butyllithium (t-BuLi)/N,N,N′,N′-tetramethylethylenediamine (TMEDA) in toluene was found to be very effective. In this system, the t-BuLi/TMEDA complex reacts with toluene to form the benzyllithium (BzLi)/TMEDA complex, and this complex initiates the Anionic Polymerization of DAS. The DASLi/TMEDA and PDASLi/TMEDA complexes have sufficient nucleophilicity and stability as propagating species, without the metalation of toluene, and as a result, living Anionic Polymerization was achieved. The high molecular weight poly(4-diphenylaminostyrene) (PDAS), synthesized using the RLi/TMEDA system, had a syndiotactic-rich configuration, independent of the Polymerization solvent.
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Anionic Polymerization of N-Vinylcarbazole with Alkyllithium as an Initiator
Macromolecules, 2006Co-Authors: Itaru NatoriAbstract:The Anionic Polymerization of N-vinylcarbazole (NVC) with alkyllithium (RLi) as an initiator was achieved for the first time. The yield of poly(N-vinylcarbazole) (PNVC) was considerably affected by the molar ratio of RLi to NVC. The Polymerization temperature, type of solvent, additives, and type of initiator influenced the Anionic Polymerization of NVC. The highest yield was obtained with tert-butyllithium (t-BuLi) as an initiator, with a molar ratio of approximately [t-BuLi]0/[NVC]0 = 0.1. Aliphatic hydrocarbons with relatively low solubility for NVC and PNVC were considered to be appropriate solvents for the Anionic Polymerization of NVC. The 1H NMR spectrum strongly supports the polymer chain structure of PNVC. The coordination of NVC nitrogen atoms to the lithium atoms of RLi presumably reduces the electron density of the vinyl group, and the Anionic Polymerization of NVC becomes possible.