• Title, Summary, Keyword: living anionic polymerization

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Synthesis of SIS Triblock Copolymer by Living Anionic Polymerization and Its Oil Gelling Capacity (리빙 음이온 중합법에 의한 SIS Triblock 공중합체의 제조 및 유류 고형화 특성)

  • Heo Jae-Joon;Lee Min-Gyu;Kim Si-Young;Ju Chang-Sik
    • Journal of Environmental Science International
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    • v.15 no.6
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    • pp.593-600
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    • 2006
  • SIS triblock copolymers, one of the major raw materials of oil gelling agent, were synthesized by living anionic polymerization and the resultant copolymers formed with various shapes and sizes were used to examine their oil gelling capacities. Coupling method was adapted to form final triblock products from diblock living polymers. Prior to polymerization, the impurities in monomers and solvents were throughly removed by killing technique. We experimentally investigated the effects of operating parameters of synthesis and forming of SIS triblock copolymers on oil gelling capacity. The photocatalytic decomposition of SIS triblock copolymer under ultraviolet circumstance was also investigated and it is found that the addition of P-25 enhances the photocatalytic decomposition.

Synthesis and Characterization of Bio-Elastomer Based on Vegetable Oils (식물성 오일 기반 바이오 탄성체의 합성과 특성)

  • Lee, Hyeok;Kwak, Kyung-Hwan;Kim, Jin-Kuk
    • Elastomers and Composites
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    • v.47 no.1
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    • pp.30-35
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    • 2012
  • Novel bio-polybutadiene polymers with controlled molecular weight (MW), MW distribution, chemical composition and micro structure were synthesized by a living anionic polymerization of butadiene and the subsequent coupling reaction of the thus obtained living polybutadiene and a vegetable oil. Anionic polymerization of butadiene was carried out in THF solvent using n-BuLi initiator. The resulting living polybutadienyllithium polymer was then reacted with epoxidized soybean oil (ESO) to obtain a star-polymer of polybutadiene and vegitable oil. Three different bio-elastomers were prepared by coupling living polybutadienes of MWs 1000, 5000 and 1000g/mol with ESO. The molecular structure and MW of the polybutadienes and bioelastomers were characterized by $^1H$-NMR, FTIR and GPC techniques.

Application of Living Ionic Polymerizations to the Design of AB-Type Comb-like Copolymers of Various Topologies and Organizations

  • Lanson, David;Ariura, Fumi;Schappacher, Michel;Borsali, Redouane;Deffieux, Alain
    • Macromolecular Research
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    • v.15 no.2
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    • pp.173-177
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    • 2007
  • Living anionic and cationic polymerizations have been combined to prepare various types of comb-like copolymers composed of polystyrene (PS) and polyisoprene (PI) blocks, with a precisely controlled architecture. According to the relative placement of these elementary building blocks, combs with randomly distributed PS and PI or with poly(styrene-b-isoprene) diblock branches (I & II, respectively) can be prepared. The reaction procedure initially includes the synthesis of a poly(chloroethylvinyl ether) using living cationic polymerization, which is used as the reactive backbone to successively graft $PS^-Li^+$ and $PI^-Li^+$ or $PI-b-PS^-Li^+$ to obtain structures (I) or (II). The synthesis of Janus-type PS-comb-b-PI-combs (III) initially involves the synthesis of a diblock backbone using living cationic polymerization, which bears two distinct reactive functions having either a protected or activated form. Living $PS^-Li^+$ and $PI^-Li^+$ are then grafted, in two separate steps, onto each of the reactive functions of the backbone, respectively.

Synthesis of Multi Hydroxyl Chain-End Functionalized Polyolefin Elastomer with Poly(t-butylstyrene) Graft (Poly(t-butylstyrene) 그라프트를 가지는 수산기 말단 관능화 폴리올레핀 탄성체의 합성)

  • Lee, Hyoung Woo;Cho, Hee Won;Lee, Sang Min;Park, Sat Byeol;Kim, Dong Hyun;Lee, Bum Jae
    • Elastomers and Composites
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    • v.48 no.1
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    • pp.10-17
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    • 2013
  • Polyolefin-g-poly(t-butylstyrene) as one of the high-temperature polyolefin-based thermoplastic elastomers was synthesized by the graft-from anionic living polymerization from the styrene moieties of the linear poly(ethylene-ter-1-hexene-ter-divinylbenzene) as a soft block to form the hard end blocks, poly(t-butylstyrene). The chemistry of the anionic graft-from polymerization involved complete lithiation of the pendant styrene unit of the soft polyolefin elastomer with sec-BuLi/TMEDA followed by the subsequent graft anionic polymerization of 4-tert-butylstyrene with Mn=10,000~30,000 g/mol. The graft-from living anionic polymerization were very effective and the grafting size increased proportionally with increasing monomer concentration and the reaction times. The synthetic methodology for the multi-hydroxyl chain-end modified polyolefin-g-poly(t-butylstyrene) was proposed by using the thiol-ene click reaction between 2-mercaptoethanol and the polyolefin-g-[poly(t-butylstyrene)-b-high vinyl polyisoprene], which was obtained from the subsequent living block copolymerization using polyolefin-g-Poly(t-butylstyrene) with isoprene. The result indicated that this process produced a new well-defined functionalized graft-type polyolefin-based TPE with high $T_g$ hard block(> $145^{\circ}C$).

Precise Synthesis of Dendron-Like Hyperbranched Polymers and Block Copolymers by an Iterative Approach Involving Living Anionic Polymerization, Coupling Reaction, and Transformation Reaction

  • Hirao Akira;Tsunoda Yuji;Matsuo Akira;Sugiyama Kenji;Watanabe Takumi
    • Macromolecular Research
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    • v.14 no.3
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    • pp.272-286
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    • 2006
  • Dendritic hyperbranched poly(methyl methacrylate)s (PMMA)s, whose branched architectures resemble the 'dendron' part(s) of dendrimer, were synthesized by an iterative methodology consisting of two reactions in each iteration process: (a) a coupling reaction of u-functionalized, living, anionic PMMA having two tert-butyldimethylsilyloxymethylphenyl(SMP) groups with benzyl bromide(BnBr)-chain-end-functionalized PMMA, and (b) a transformation reaction of the introduced SMP groups into BnBr functionalities. These two reactions, (a) and (b), were repeated three times to afford a series of dendron-like, hyperbranched (PMMA)s up to third generation. Three dendron-like, hyperbranched (PMMA)s different in branched architecture were also synthesized by the same iterative methodology using a low molecular weight, functionalized 1,1-diphenylalkyl anion prepared from sec-BuLi and 1,1-bis(3-tert-butyldime-thylsilyloxymethylphenyl)ethylene in the reaction step (b) in each iterative process. Furthermore, structurally similar, dendron-like, hyperbranched block copolymers could be successfully synthesized by the iterative methodology using $\alpha$-functionalized, living, anionic poly(2-(perfluorobutyl) ethyl methacrylate) (PRfMA) in addition to $\alpha$-functionalized, living PMMA. Accordingly, the resulting block copolymers were comprised of both PMMA and PRfMA segments with different sequential orders. After the block copolymers were cast into films and annealed, their surface structures were characterized by angle-dependent XPS and contact angle measurements. All three samples showed significant segregation and enrichment of PRfMA segments at the surfaces.

Living Anionic Polymerization of Isocyanates

  • Lee, Jae-Suk
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.198-198
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    • 2006
  • We have identified sodium benzanilide (Na-BA), sodium diphenyl amine (Na-DPA) and sodium deoxibenzoin (Na-DB) as very efficient initiators for the living anionic polymerization of HIC. It has a slow propagation rate with the additive function of chain end protection, offering in the process a perfect control over MW and MWD. The well-defined amphiphilic coil-rod, coil-rod-coil, and rod-coil-rod block-copolymers of PHIC and P2VP with controlled architecture have been synthesized for the first time with ${\sim}100\;%$ yields. The resulting block copolymers showed lamellar film, donuts, solid and hollow micelles, by simply varying the solvents and the block compositions.

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Control of Block Copolymer Microdomain: In-Situ and Real-Time SANS Studies of Polymerization-Induced Self-assembly of Block Copolymer Microdomain Structure

  • Koizumi, Satoshi;Yamauchi, Kazuhiro;Hasegawa, Hirokazu;Tanaka, Hirokazu;Motokawa, Ryuhei;Hashimoto, Takeji
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.71-72
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    • 2006
  • We investigated a simultaneous living anionic polymerization process of isoprene (I) and 4styrene-d_8$ (S) in $benzene-d_6$ as a solvent with sec-buthyllithium as an initiator into polyisoprene(PI)-block-poly($styrene-d_8$)(PS) and the polymerization-induced molecular self-assembling process. This process was observed in-situ by time-resolved small-angle neutron scattering (SANS) experiment. The SANS profiles measured exhibited three time regions, where (i) the selective growth of PI chains occurs; (ii) the living chain ends switch from isoprenyllithium to styryllithium, and (iii) the SANS exhibited the polymerization induced disorder-to-order transition and order-to-order transition.

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Successive Synthesis of Well-Defined Star-Branched Polymers by an Iterative Approach Based on Living Anionic Polymerization

  • Higashihara Tomoya;Inoue Kyoichi;Nagura Masato;Hirao Akira
    • Macromolecular Research
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    • v.14 no.3
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    • pp.287-299
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    • 2006
  • To successively synthesize star-branched polymers, we developed a new iterative methodology which involves only two sets of the reactions in each iterative process: (a) an addition reaction of DPE or DPE-functionalized polymer to a living anionic polymer, and (b) an in-situ reaction of 1-(4-(4-bromobutyl)phenyl)-1-phenylethylene with the generated 1,1-diphenylalkyl anion to introduce one DPE functionality. With this methodology, 3-, 4-, and 5-arm, regular star-branched polystyrenes, as well as 3-arm ABC, 4-arm ABCD, and a new 5-arm ABCDE, asymmetric star-branched polymers, were successively synthesized. The A, B, C, D, and E arm segments were poly(4-trimethylsilylstyrene), poly(4-methoxystyrene), poly(4-methylstyrene), polystyrene, and poly(4-tert-butyldimethylsilyloxystyrene), respectively. All of the resulting star-branched polymers were well-defined in architecture and precisely controlled in chain length, as confirmed by SEC, $^1H$ NMR, VPO, and SLS analyses. Furthermore, we extended the iterative methodology by the use of a new functionalized DPE derivative, 1-(3-chloromethylphenyl)-1-((3-(1-phonyletheny1)phenyl) ethylene, capable of introducing two DPE functionalities via one DPE anion reaction site in the reaction (b). The number of arm segments of the star-branched polymer synthesized by the methodology could be dramatically increased to 2, 6, and up to 14 by repeating the iterative process.

Anionic Synthesis of Dipyridine Chain End-Functionalized Polystyrene and Polybutadiene (리빙 음이온 중합에 의한 Dipyridine 말단 관능화 폴리스티렌 및 폴리부타디엔의 합성)

  • Ji, Sang-Chul;Lee, Jong-Seop;Kim, Doo-Hwan;Kang, Cheol-Han;Park, Jong-Hyuk;Lee, Bum-Jae
    • Polymer(Korea)
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    • v.34 no.2
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    • pp.159-165
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    • 2010
  • Dipyridine-terminated polystyrenes and polybutadienes were synthesized by the chain endfunctionalization reaction of polystyryllithium (PSLi) and polybutadienyllithium (PBDLi) with di(2-pyridyl) ketone(DPK) using a living anionic polymerization method in the Ar-glove box. Living polymeric lithiums with low molecular weights (Mw=1000~2000 g/mol) were used to investigate the chain end-functionalization yield with DPK and the degree of coupling reaction by the attack of organolithium to the pyridine ring in the presence of TMEDA using GPC, $^1H$-NMR, $^{13}C$ analysis. DPK-terminated PBD exhibited much higher functionalization yield and less amount of coupling reaction compared with DPK-terminated PS. 86% functionalization yield with 9% degree of coupling was obtained when the PBDLi was added dropwise to DPK solution at room temperature. The functionalization yield was increased as the reaction temperature decreased, however, no LiCl effect was observed in this chain end-functionalization reaction with DPK.

Synthesis and Characterization of Aliphatic Polyether Dendrons Based on Polystyrene Peripheries

  • Song, Jie;Kim, Hyun-Yu;Cho, Byoung-Ki
    • Bulletin of the Korean Chemical Society
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    • v.28 no.10
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    • pp.1771-1776
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    • 2007
  • The synthesis of well-defined dendrons based on aliphatic polyether dendritic cores and glassy polystyrene peripheries is described. The synthetic route involves a combination of living anionic polymerization and a stepwise convergent method consisting of iterative Williamson etherification and hydroboration/oxidation reactions. On the basis of molecular weight, as characterized by gel permeation chromatography (GPC), the first generation dendron (Generation-1) shows a random coil conformation like a linear polystyrene, while higher generations (Generation-2 and 3) reveal globular forms in solution.