Anionic Polymerization

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Akira Hirao - One of the best experts on this subject based on the ideXlab platform.

Jimmy W. Mays - One of the best experts on this subject based on the ideXlab platform.

  • poly 1 adamantyl acrylate living Anionic Polymerization block coPolymerization and thermal properties
    Macromolecules, 2016
    Co-Authors: Wei Lu, Nam-goo Kang, Kunlun Hong, Caili Huang, Jimmy W. Mays
    Abstract:

    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...

  • Poly(1-adamantyl acrylate): Living Anionic Polymerization, Block CoPolymerization, and Thermal Properties
    2016
    Co-Authors: Caili Huang, Nam-goo Kang, Kunlun Hong, Jimmy W. Mays
    Abstract:

    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

  • High Vacuum Techniques for Anionic Polymerization
    Anionic Polymerization, 2015
    Co-Authors: Kedar Ratkanthwar, Nikolaos Hadjichristidis, Jimmy W. Mays
    Abstract:

    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.

  • Schlenk Techniques for Anionic Polymerization
    Anionic Polymerization, 2015
    Co-Authors: Kedar Ratkanthwar, Nikolaos Hadjichristidis, Junpeng Zhao, Hefeng Zhang, Jimmy W. Mays
    Abstract:

    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.

  • Experimental techniques in high‐vacuum Anionic Polymerization
    Journal of Polymer Science Part A: Polymer Chemistry, 2005
    Co-Authors: David Uhrig, Jimmy W. Mays
    Abstract:

    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.

  • Living Anionic Polymerization of 1,4-divinylbenzene and its derivatives
    Reactive and Functional Polymers, 2018
    Co-Authors: Raita Goseki, Takashi Ishizone, Shunsuke Tanaka, Akira Hirao
    Abstract:

    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

  • Materials Science and Technology - Anionic Polymerization: Recent Advances
    Materials Science and Technology, 2012
    Co-Authors: Takashi Ishizone, Akira Hirao
    Abstract:

    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

  • Anionic Polymerization of Protected Functional Monomers
    Polymer Science: A Comprehensive Reference, 2012
    Co-Authors: Takashi Ishizone, Kenji Sugiyama, Akira Hirao
    Abstract:

    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.

  • living Anionic Polymerization of n methacryloylazetidine Anionic polymerizability of n n dialkylmethacrylamides
    Macromolecules, 2010
    Co-Authors: Takashi Suzuki, Junichi Kusakabe, Keita Kitazawa, Takeshi Nakagawa, Susumu Kawauchi, Takashi Ishizone
    Abstract:

    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...

  • Recent advance in living Anionic Polymerization of functionalized styrene derivatives
    Progress in Polymer Science, 2002
    Co-Authors: Akira Hirao, Surapich Loykulnant, Takashi Ishizone
    Abstract:

    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.

Itaru Natori - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of functionalized fullerene-C60 by the living Anionic Polymerization technique
    Journal of Applied Polymer Science, 2010
    Co-Authors: Itaru Natori, Shizue Natori, Yuto Hirose
    Abstract:

    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.

  • Anionic Polymerization of 9-vinylanthracene with the alkyllithium/amine system
    Polymers for Advanced Technologies, 2009
    Co-Authors: Itaru Natori, Shizue Natori
    Abstract:

    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.

  • Anionic Polymerization of 4 diphenylaminostyrene characteristics of the alkyllithium n n n n tetramethylethylenediamine system for living Anionic Polymerization
    Macromolecules, 2008
    Co-Authors: Itaru Natori, Shizue Natori, Hiroaki Usui, Hisaya Sato
    Abstract:

    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.

  • Anionic Polymerization of 4-Diphenylaminostyrene : Characteristics of the Alkyllithium/N,N,N',N'-Tetramethylethylenediamine System for Living Anionic Polymerization
    Macromolecules, 2008
    Co-Authors: Itaru Natori, Shizue Natori, Hiroaki Usui, Hisaya Sato
    Abstract:

    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.

  • Anionic Polymerization of N-Vinylcarbazole with Alkyllithium as an Initiator
    Macromolecules, 2006
    Co-Authors: Itaru Natori
    Abstract:

    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.