Mayumi Hayashi

Synthesis of well-defined functionalized polymers and star branched polymers by means of living anionic polymerization using specially designed 1,1-diphenylethylene derivatives

This article covers precise syntheses of well-defined chain-end and in-chain functionalized polymers, multi-functionalized polymers with a definite number of functional groups, star-branched and graft polymers by recently developed methodologies using specially designed 1,1-diphenylethylene (DPE) derivatives. The DPE derivatives include various substituted DPE derivatives with functional groups and their derivatives, DPE-functionalized DPE derivatives, and well-defined DPE-functionalized macromonomers. The synthetic utility and importance of these DPE derivatives are described via such polymer syntheses.

Combining living anionic polymerization with branching reactions in an iterative fashion to design branched polymers.

This paper reviews the precise synthesis of many-armed and multi-compositional star-branched polymers, exact graft (co)polymers, and structurally well-defined dendrimer-like star-branched polymers, which are synthetically difficult, by a commonly-featured iterative methodology combining living anionic polymerization with branched reactions to design branched polymers. The methodology basically involves only two synthetic steps; (a) preparation of a polymeric building block corresponding to each branched polymer and (b) connection of the resulting building unit to another unit. The synthetic steps were repeated in a stepwise fashion several times to successively synthesize a series of well-defined target branched polymers.

Synthesis of Branched Polymers by Means of Living Anionic Polymerization, 8. Synthesis of Well-Defined Star-Branched Polymers by an Iterative Approach Based on Living Anionic Polymerization Using 1,1-Diphenylethylene Derivatives

The synthesis of well-defined four- and six-arm star branched polymers in which arms differ either in molecular weight or composition has been achieved via a new iterative approach based on living anionic polymerization using 1,1-diphenylethylene (DPE) derivatives. Each stage in the iteration involves two reactions: a living functionalization reaction of living anionic polymer with DPE derivatives and an in-situ reaction of the resulting linked product having two anions with 1-4-(4-bromobutyl)phenyl]-1-phenylethylene to introduce two DPE moieties into the polymer. In each living functionalization reaction, a 1.2-fold excess or more of living anionic polymer relative to DPE moiety was employed to complete the reaction. Asymmetric A2A′2 and A2A′2A′′2 star-branched polystyrenes as well as A2B2 and A2B2C2 heteroarm star-branched polymers were synthesized by repeating the iteration synthetic sequence two and three times, respectively. Since the polymers obtained by each reaction stage were contaminated with their precursor polymers, they were isolated by SEC fractionation. Their high degrees of compositional, molecular weight and architectural homogeneity were confirmed by the analytical results of SEC, SLS, VPO, 1H NMR and viscosity measurements.

Synthesis of well‐defined multifunctionalized polystyrenes with benzyl bromide moieties by a novel iterative divergent approach

Well-defined chain-end-functionalized polystyrenes with two, four, eight, sixteen, and thirty-two benzyl bromide moieties were synthesized by the methodology based on a novel iterative divergent approach. In this methodology, the entire iterative synthetic sequence involves only two sets of the reactions: a coupling reaction of the terminal benzyl bromide moieties with the functionalized anion prepared from 1,1-bis(3-tert-butyldimethylsilyloxymethylphenyl)ethylene and sec-BuLi and a transformation reaction of the introduced tert-butyldimethylsilyloxymethyl groups into bromomethyl functions by treatment with LiBr-(CH 3 ) 3 SiCl. The iteration started with chain-end-functionalized polystyrene with one benzyl bromide moiety and could be repeated five times. All iterations proceeded quantitatively to afford chain-end-functionalized polystyrenes with a definite number of benzyl bromide moieties up to thirty-two.

Synthesis of Well-Defined Chain-End and In-Chain-Functionalized Polystyrenes with a Definite Number of α-Methylstyrene, D-Glucose, Phenol, and Benzyl Halide Functionalities by Reactions of Chloro (or Bromo) methylphenyl-Functionalized Polystyrenes with Substituted 1,1-Diphenylalkyllithiums

Chain-end and in-chain functionalized polystyrenes with four α-methylstyrene, eight D-glucose, eight phenol, eight benzyl chloride, four benzyl bromide functionalities with well-defined structures were successfully synthesized by the reactions of well-defined chain-end and in-chain functionalized polystyrenes with four chloro (or bromo)methylphenyl groups and substituted 1,1-diphenylalkyllithiums. They were prepared from sec-butyllithium (sec-BuLi) and the following substituted 1,1-diphenylethylene derivatives: 1,1-bis{3-[(1,2:5,6-di-O-isopropylidene-a-D-glucofuranose-O-3-yl)methyl]phenyl)ethylene (1), 1,1-bis(3-methoxymethylphenyl)ethylene (2), 1-{4-[3-(4-isopropenyl-phenyl)propyl]phenyl]-1-phenylethylene (3), 1,1-bis(4-tert-butyldimethylsilyloxyphenyl)ethylene (4), and 1,1-bis(3-tert-butyldimethylsilyloxymethylphenyl) ethylene (5). In 20 h at -78°C all reactions proceeded cleanly and efficiently in THF to afford quantitatively the expected well-defined functionalized polystyrenes. Advantages of these reactions are described in this paper.

Anionic living polymerization of functional monomers. Precise synthesis of various functionalized polystyrenes with monosaccharide residues by anionic living polymerization and living functionalization reaction

*Entered Department of Polymer Chemistry, Faculty of Engineering, Tokyo Institute of Technology (Japan), April 1993, and graduated March 1997, B. Eng. *Entered Department of Polymer Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology (Japan), April 1997, and graduated March 1999, M. Eng. Thesis Theme: Anionic Polymerization of Styrene Derivatives Containing Monosaccharide Residues. *Entered Polymeric and Organic Materials Department, Graduate School of Science and Engineering, Tokyo Institute of Technology (Japan), April 1999, and graduated March 2002, D. Eng. Thesis Theme: Precise Synthesis of Monosaccharide-Functionalized Polymers by Means of Living Anionic Polymerization.

Living Anionic Polymerization of Monomers with Functional Groups, 15. Anionic Polymerization and Reaction of Styrene and 1,1-Diphenylethylene Derivatives Substituted with Alkoxymethyl Groups

Anionic polymerizations of ortho-, meta-, and para-substituted styrene derivatives with alkoxy-methyl groups have been studied. It was found that their polymerization behaviors were significantly affected by the substituted position of the alkoxymethyl group. The meta- and ortho-substituted styrenes successfully underwent living anionic polymerization in THF at -78°C with the initiators having K + as a counter cation such as cumyl-potassium and oligo (α-methylstyryl ) potassium, and potassium napthalenide. On the other hand, no appreciable polymerization of the para-substituted styrenes occured under the identical conditions. The similar positional effect was also observed in the reactions of polystyryl-lithium with o,o-, m,m-, and p,p-disubstituted 1,1-diphen-ylethylene (DPE) derivatives with methoxymethyl groups. Instead of the expected 1 : 1 addition products, undesirable high molecular weight polymers were formed especially using p,p-disubstituted DPE. In order to account for such anomalous polymerization and reaction behaviors of the para-substituted styrene and DPE derivatives, we postulated the reaction pathway based on the anion-mediated rearrangement followed by a 1,6-elimination reaction to produce very reactive p-xylylene and/or biradical inter-mediates that were coupled to each other. This postulated reaction pathway was discussed throughout the results of the stoichiometric reaction of sec-BuLi with p-methoxy-methylstyrene and 1-(4-methoxymethylphenyl)-1-pheny-lethylene.

Development of a micro-satellite TSUBAME for X-ray polarimetry of GRBs

TSUBAME is a micro-satellite that the students of Tokyo Institute of Technology took the lead to develop for measuring hard X-ray polarization of Gamma-Ray Bursts(GRBs) in order to reveal the nature of the central engine of GRBs. TSUBAME has two instruments: Wide-field Burst Monitor (WBM) and Hard X-ray Compton Polarimeter (HXCP). We aim to start observing with HXCP in 15 seconds by pointing the spacecraft using Control Moment Gyro. In August 2014, we assembled TSUBAME and performed an integration test during ~2 weeks.TSUBAME by communication tests with Cute-1.7+APDII in orbit. On Nov 6 2014, TSUBAME was launched from Russia and it was put into Sun-synchronous orbit at 500 km above the ground. However, serious trouble occurred to the ham radio equipment. Therefore we could not start up the X-ray sensors until Feb 10 2015. In this paper, we report the system of TSUBAME and the progress after the launch.

Star-Branched Polymers (Star Polymers)

The synthesis of well-defined regular and asymmetric mixed arm (hereinafter miktoarm) star-branched polymers by the living anionic polymerization is reviewed in this chapter. In particular, much attention is being devoted to the synthetic development of miktoarm star polymers since 2000. At the present time, the almost all types of multiarmed and multicomponent miktoarm star polymers have become feasible by using recently developed iterative strategy. For example, the following well-defined stars have been successfully synthesized: 3-arm ABC, 4-arm ABCD, 5-arm ABCDE, 6-arm ABCDEF, 7-arm ABCDEFG, 6-arm A2B2C2, 9-arm A3B3C3, 12-arm A4B4C4, 13-arm A4B4C4D, 9-arm AB8, 17-arm AB16, 33-arm AB32, 7-arm AB2C4, 15-arm AB2C4D8, and 31-arm AB2C4D8E16 miktoarm star polymers, most of which are quite new and difficult to synthesize by the end of the 1990s. Several new specialty functional star polymers composed of vinyl polymer segments and rigid rodlike poly(acetylene) arms, helical polypeptide, or helical poly(hexyl isocyanate) arms are introduced.

Branched Polymers. II. Well-Defined Heteroarm Star-Branched Polymers by Means of Living Anionic Polymerization.

リビングアニオン重合を用いた星型高分子, なかでも分子量や種類が異なる腕セグメントから構成されるヘテロアームスターポリマー合成に関する最近の進歩について述べる. 構造が厳密に規制されたヘテロアームスターポリマー合成は極めて困難なため, そのほとんどが90年代になって報告されている. 現時点までの合成例は, 大きく2つに分けられる. 第1は多官能クロロシランを結合試薬として用い, リビングアニオンポリマーの立体障害による反応性の違いを利用して, 順次結合させていく方法であり, 第2はマクロモノマーを用い, 結合反応と重合反応を組み合わせた方法である. 最近筆者らは, ポリマー鎖中にクロロメチルフェニル基 (ベンジル塩化物) の導入個数と導入位置を厳密に規制する方法を開発し, 構造が明確な鎖末端, 鎖中に2～16個導入した新規のクロロメチルフェニル化ポリマーの合成に成功した. これらのポリマーにリビングアニオンポリマーを反応させることで, さまざまな構造のヘテロアームスターポリマーの系統的合成が可能になった. さらにリビングポリマーと末端に1,1-ジフェニルエチレンを有するポリマーを反応させることで得られる, 1本のポリマー鎖からなり, その反応結合点にアニオンを有するポリマーアニオンを用い, クロロメチルフェニル基1個当たりに2本のポリマー鎖を導入するまったく新しい方法を展開し, 新しいタイプのヘテロアームスターポリマーの合成に成功した.