Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 47 Issue 2

15 January 2009

Volume 47, Issue 2

Pages 319–652

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      Jacketed polymers: Controlled synthesis of mesogen-jacketed polymers and block copolymers (pages 319–330)

      Long-Cheng Gao, Xing-He Fan, Zhi-Hao Shen, Xiaofang Chen and Qi-Feng Zhou

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23128

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      In the Highlight Article, we review the controlled radical polymerization of mesogen-jacketed liquid crystalline polymers (MJLCPs) on linear homopolymers, star polymers, superbranched polymers, graft polymers, block copolymers, star block copolymers, and so on. The potential application of MJLCPs are discussed and explored. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

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    3. Articles
    1. Correlation of free radical copolymerization behavior and copolymer properties with the strength of π-π stacking interactions between aromatic fluorocarbons and aromatic hydrocarbons: Comparison of the copolymerization behavior of 2,3,4,5,6-pentafluorostyrene with styrene, 1-vinylnaphthalene and 2-vinylnaphthalene (pages 331–345)

      Coleen Pugh, Marta Paz-Pazos and Chau N. Tang

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23132

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      2,3,4,5,6-Pentafluorostyrene (PFS) was copolymerized with 1-vinylnaphathalene in bulk by radical copolymerization at 25 °C, 70 °C and 120 °C, and with 2-vinylnaphathalene at 70 °C. Their reactivity ratios were determined at low monomer conversions using the nonlinear least-squares method of analysis, which demonstrated that both comonomer pairs tend to alternate, and that their alternating tendency increases with decreasing temperature, similar to the radical copolymerizations of PFS with styrene in bulk. The glass transition temperatures determined by differential scanning calorimetry are elevated relative to their mole-average values, with the extent of elevation correlating with the strength of the intramolecular π-π stacking interactions.

    2. Facile postpolymerization end-modification of RAFT polymers (pages 346–356)

      Jason M. Spruell, Benjamin A. Levy, Alexander Sutherland, William R. Dichtel, Joy Y. Cheng, J. Fraser Stoddart and Alshakim Nelson

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23138

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      One-pot methods for the endgroup modification of RAFT polymers were investigated. Dithioester terminated polymers were transformed into ω-functionalized polymers through conjugate addition of a variety of acrylates via an intermediate thiol. These routes provide a versatile approach for introducing functionality at the polymer terminus, which influences the self assembly behavior of the polymer. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    3. Imino-indolate half-titanocene chlorides: Synthesis and their ethylene (co-)polymerization (pages 357–372)

      Weiwei Zuo, Min Zhang and Wen-Hua Sun

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23139

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      A series of imino-indolate half-titanocene chlorides, Cp′Ti(L)Cl2 (C1C7: Cp′ = C5H5, MeC5H4, C5Me5, L = imino-indolate ligand), was synthesized by the reaction of Cp′TiCl3 with sodium imino-indolates. These complexes showed good catalytic activities for ethylene polymerization and ethylene/1-hexene copolymerization. Moreover, the copolymerization of ethylene and methyl 10-undecenoate was demonstrated using the C1/MAO catalytic system.

    4. Magnetic field effects on the copolymerization of water-soluble and ionic monomers (pages 373–383)

      Ignacio Rintoul and Christine Wandrey

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23152

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      The effect of magnetic field (MF) on the radical copolymerization of water-soluble monomers (acrylamide, acrylic acid, sodium acrylate, diallyldimethylammonium chloride) is presented. The polymerization rates (Rp) increased up to 65% but the copolymer compositions were not affected when a MF of 0.1 Tesla was applied. The electrostatic repulsion between monomers and radicals dominates Rp and governs the copolymer composition with and without MF. It is of practical interest that MF has the potential to reduce the production time in a non-contact, homogeneous and instantaneous manner without modifying the product composition while keeping constant other reaction conditions.

    5. Synthesis and characterization of partially disulfonated hydroquinone-based poly(arylene ether sulfone)s random copolymers for application as proton exchange membranes (pages 384–391)

      Abhishek Roy, Michael A. Hickner, Brian R. Einsla, William L. Harrison and James E. McGrath

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23153

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      Partially disulfonated hydroquinone-based poly(arylene ether sulfone)s random copolymers were synthesized and characterized for application as proton exchange membranes. When compared with existing biphenol-based disulfonated poly(arylene ether sulfone)s (BPSH-xx) random copolymers, a similar relationship between selectivity (proton conductivity over methanol permeability) and methanol permeability was observed for both series of copolymers as shown in the figure. The HQSH-xx copolymers showed significantly lower methanol permeability and high selectivity when compared with the state of the art Nafion® 117 copolymer. Because hydroquinone is less expensive than biphenol, the HQSH-xx system has a distinct economic advantage over the BPSH-xx copolymers.

    6. Photoinitiating monomers based on di- and triacryloylated hydroxylamine derivatives (pages 392–403)

      Claudia Dworak, Stefan Kopeinig, Helmuth Hoffmann and Robert Liska

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23156

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      Radical photopolymerization is a widely used tool for the curing of thin films within the fraction of a second. In this article, we describe the development of a new type of photoreactive monomer that is not only able to polymerize but also absorbs light and subsequently initiates the polymerization. Photo-DSC experiments of these hydroxylamine-based monomers have proven similar reactivity to commercially applied Type II photoinitiator system consisting of benzophenone and triethanolamine. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]

    7. Synthesis of well-defined 7-arm and 21-arm poly(N-isopropylacrylamide) star polymers with β-cyclodextrin cores via click chemistry and their thermal phase transition behavior in aqueous solution (pages 404–419)

      Jian Xu and Shiyong Liu

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23157

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      The syntheses of well-defined 7-arm and 21-arm poly(N-isopropylacrylamide) (PNIPAM) star polymers possessing β-cyclodextrin (β-CD) cores were achieved via the combination of atom transfer radical polymerization (ATRP) and click reactions. The thermal phase transition behavior of the obtained star polymers with varying molecular weights (MW) were examined by temperature-dependent turbidity and micro-differential scanning calorimetry (micro-DSC). [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    8. Synthesis and radical polymerization of dissymmetric fumarates with alkoxyethyl and bulky siloxy groups (pages 420–433)

      Masato Ohnishi, Takahiro Uno, Masataka Kubo and Takahito Itoh

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23159

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      Amphiphilic dissymmetric fumarate derivatives (1ac) having both an alkoxyethyl group and a bulky 3-[tris(trimethylsiloxy)silyl]propyl group were synthesized as the contact lens materials, and their radical homopolymerizations, copolymerizations with styrene (St), and thermal properties of the resulting polymers were investigated. And also, preparation of membranes containing 1a unit and properties of the resulting polymers in the points of oxygen permeability, water uptake and transparency were investigated.

    9. Facilitation effect of oligonucleotide on vesicle formation from single-chained cationic surfactant—Dependences of oligonucleotide sequence and size and surfactant structure (pages 434–449)

      Xia Guo, Bo Cui, Hua Li, Zhiyun Gong and Rong Guo

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23160

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      Oligo d(T)n cannot induce vesicle formation from single-chained cationic surfactant molecules, whereas the other oligonucleotides can. Moreover, the oligonucleotide with a bigger size or with a hairpin structure favors vesicle formation more, and the increases in the size of the head group and/or the length of the alkyl group of surfactant decrease the facilitation efficiency of oligonucleotide.

    10. Phase separation of polymer-functionalized SWNTs within a PMMA/polystyrene blend (pages 450–458)

      James D. Mayo, Sonia Behal and Alex Adronov

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23161

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      The synthesis of single-walled carbon nanotubes covalently functionalized with polystyrene (PS) or poly(methyl methacrylate) (PMMA) was carried out using “click” chemistry. The resulting polymer-functionalized nanotubes were then added to PS/PMMA blends, and the phase separation behavior of the resulting composites upon thermal annealing was investigated to determine if the nanotube-bound polymers can dictate the bulk polymer phase in which the nanotubes end up. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    11. Revisit to the formation mechanism of exfoliated montmorillonite/PMMA nanocomposite latex through soap-free emulsion polymerization (pages 459–466)

      Keng-Jen Lin, Chi-An Dai and King-Fu Lin

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23163

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      In soap-free emulsion polymerization to prepare the exfoliated MMT/PMMA nanocomposite latex, the polymerizing ionic radicals are a major component to diffuse into the gallery of MMT. They have been observed to organize into disc-like micelles in the interlayer regions that exfoliated MMT. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    12. Immobilization of RAFT agents on silica nanoparticles utilizing an alternative functional group and subsequent surface-initiated RAFT polymerization (pages 467–484)

      Yingkui Yang, Zhifang Yang, Qiang Zhao, Xinjian Cheng, Sie Chin Tjong, Robert Kwok Yiu Li, Xiaotao Wang and Xiaolin Xie

      Article first published online: 9 DEC 2008 | DOI: 10.1002/pola.23164

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      RAFT chain transfer agents (CTAs) were attached to silica particles by a silane coupling reaction with macro-RAFT agents containing γ-methacryloxypropyltrimethoxysilane (MPS) moieties. The resulting silica-CTAs can on one hand induce other monomer growth from the supports by further RAFT polymerization, forming silica-polymer core-shell particles. On the other hand, neither Z nor R groups within CTAs are directly anchored onto the backbone, but mediated by MPS units, which opens novel opportunities to improve the limitation caused by both Z- and R-mediated traditional approaches. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    13. Synthesis of sulfonated aromatic poly(ether amide)s and their application to proton exchange membrane fuel cells (pages 485–496)

      Tae Soo Jo, Coreen H. Ozawa, Bryce R. Eagar, Lacie V. Brownell, Daehyun Han and Chulsung Bae

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23165

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      A series of wholly aromatic sulfonated poly(ether amide)s (SPEAs) containing a sulfonic acid group on the dicarbonyl aromatic ring were prepared via a polycondensation reaction of sulfonated terephthalic acid (STA), terephthalic acid (TA), and aromatic diamine monomers. The degree of sulfonation was readily controlled by adjusting the monomer feed ratio of STA and TA in the polymerization process. In proton conductivity measurements, ODA-SPEA-70 (IEC = 1.80 mequiv/g), which was obtained from polycondensation of 4,4′-oxydianiline and 70 mol% STA, showed a comparable proton conductivity (105 mS/cm) to that of Nafion 117 at 80 °C.

    14. ROMP-NMP-ATRP combination for the preparation of 3-miktoarm star terpolymer via click chemistry (pages 497–504)

      Aziz Gozgen, Aydan Dag, Hakan Durmaz, Okan Sirkecioglu, Gurkan Hizal and Umit Tunca

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23166

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      A combination of ring opening metathesis polymerization (ROMP) and click chemistry approach is first time utilized in the preparation of 3-miktoarm star terpolymer. The bromide end-functionality of monotelechelic poly(N-butyl oxanorbornene imide) (PNBONI-Br) is first transformed to azide and then reacted with polystyrene-b-poly(methyl methacrylate) copolymer with alkyne at the junction point (PS-b-PMMA-alkyne) via click chemistry strategy, producing PS-PMMA-PNBONI 3-miktoarm star terpolymer. PNBONI-Br was prepared by ROMP of N-butyl oxanorbornene imide (NBONI) 1 in the presence of (Z)-but-2-ene-1,4-diyl bis(2-bromopropanoate 2 as terminating agent. PS-b-PMMA-alkyne copolymer was prepared successively via nitroxide mediated radical polymerization (NMP) of St and atom transfer radical polymerization (ATRP) of MMA.

    15. Influence of alkoxy tail length and unbalanced mesogenic core on phase behavior of mesogen-jacketed liquid crystalline polymers (pages 505–514)

      Si Chen, Lan-Ying Zhang, Long-Cheng Gao, Xiao-Fang Chen, Xing-He Fan, Zhihao Shen and Qi-Feng Zhou

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23167

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      A series of MJLCPs, poly[4,4′-bis(4-alkoxyphenyl)-2-vinylbiphenyl(carboxide)] (nC2Vp, n is the number of the carbons in the alkoxy groups, n = 2, 4, 6, 8, 10, and 12) were designed and synthesized successfully via free radical polymerization. Comparing with the butoxy analog, the polymer with unbalanced mesogenic core and shorter flexible substituents (n = 2 and 4) keeps the same liquid crystalline phase, but those with longer terminal flexible substituents (n = 6, 8, 10, and 12) can develop into a well-defined smectic C (SC) phase instead of smectic A (SA) phase. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    16. Solubility behavior of amphiphilic block and random copolymers based on 2-ethyl-2-oxazoline and 2-nonyl-2-oxazoline in binary water–ethanol mixtures (pages 515–522)

      Hanneke M. L. Lambermont-Thijs, Richard Hoogenboom, Charles-André Fustin, Cécile Bomal-D'Haese, Jean-François Gohy and Ulrich S. Schubert

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23168

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      The solution properties of random and block copolymers consisting of 2-ethyl-2-oxazoline (EtOx) and 2-nonyl-2-oxazoline (NonOx) is investigated in binary water–ethanol solvent mixtures. Solubility phase diagrams were determined for random and block EtOx-NonOx copolymers with compositions ranging from pure EtOx to pure NonOx. A variety of solution properties were observed using these water–ethanol mixtures, including dispersion formation, dissolution at elevated temperatures, lower and upper critical solution behavior, and micellization. Significant differences were observed for the solution properties of the random and block copolymers, which are discussed in detail in correlation to the molecular structure of the copolymers. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    17. Investigation of ABn (n = 2, 4) type hyperbranched polymerization with cyclization and steric factors: Influences of monomer concentration, reactivity, and substitution effect (pages 523–533)

      Long Wang and Xuehao He

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23169

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      ABn (n = 2,4) type hyperbranched polymerization is studied via a 3D Monte Carlo lattice model. Steric factors, intramolecular rings, and molecular diffusion show great influence on polymerization reactions. Parameters of hyperbranched polymers are strongly depend on monomer concentration, however not on reaction activity. When compared with theoretical predictions, the simulation results are closer to experimental data. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    18. Disperse red 1 end capped oligoesters. Synthesis by noncatalyzed ring opening oligomerization and structural characterization (pages 534–547)

      Cristian Peptu, Valeria Harabagiu, Bogdan C. Simionescu, Grazyna Adamus, Marek Kowalczuk and Jean-Michel Nunzi

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23170

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      The noncatalyzed ring opening oligomerization of cyclic esters in the presence of Disperse Red 1, at high temperatures (100 °C for ε-caprolactone and 130 °C for D,L-lactide) is described. As proved by ESI MS/MS and MALDI ToF MS with support of NMR, well defined azofunctional oligoesters are obtained.

    19. Long-lived layered silicates-immobilized 2,6-bis(imino)pyridyl iron (II) catalysts for hybrid polyethylene nanocomposites by in situ polymerization: Effect of aryl ligand and silicate modification (pages 548–564)

      Giuseppe Leone, Fabio Bertini, Maurizio Canetti, Laura Boggioni, Lucia Conzatti and Incoronata Tritto

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23172

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      Heterogeneous-layered silicate-immobilized 2,6-bis(imino)pyridyl iron (II) dichloride/MMAO catalysts, in which the active polymerization species are intercalated within the layered host system were prepared for producing hybrid partially exfoliated polyethylene (PE) nanocomposites. The ethylene polymerization catalyzed by the intergallery-anchored catalysts is more efficient and produce PE with higher molar masses than the analogous homogeneous systems. In addition, thermal, structural, and morphological characterization showed that it is possible to tune the morphology of the nanocomposites as well as the final PE properties by changing the nature of the silicate and the ligand environment around the iron metallic centre.

    20. Transition metal complexes of tetradentate and bidentate Schiff bases as catalysts for ethylene polymerization: Effect of transition metal and cocatalyst (pages 565–575)

      Marzena Białek, Krystyna Czaja and Ewelina Szydło

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23173

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      Transition metal complexes with two [O,N]-type ligands or one tetradentate [O,N,N,O]-ligand were used as a precatalyst for ethylene polymerization. The effects of the central atom type (Ti, V, Zr), ligand and activator type (MAO, Et3-nAlCln, n = 0–2) on catalyst activity and polymerization properties were verified. Interestingly, the titanium complexes in combination with Et2AlCl produce polyethylene with low molecular weight, which is also accompanied by oligomers, while other catalytic systems give high molecular weight linear polyethylene.

    21. N-methylpicolinium derivatives as the coinitiators in photoinitiating systems for vinyl monomers polymerization (pages 576–588)

      Janina Kabatc and Jerzy Pączkowski

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23175

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      Addition of N-methylpicolinium derivatives as a second co-initiator into N,N′-diethylcarbocyanine—n-butyltriphenylborate (P19B2) photoinitiating system visibly increases the efficiency of polymerization photoinitiation. The cyanine dyes are able to start a specific chain of an electron transfer reaction involving different additives (borate salt and N-alkylpicolinium derivatives), giving as a result one photon—two-radicals photochemical response. The primary photochemical reaction involves an electron transfer from the n-butyltriphenylborate anion to the excited singlet state of the dye, followed by the reaction of the N-methylpicolinium derivative with the resulting dye radical to regenerate the original dye. This reaction simultaneously produces a N-methylpyridyl radical, which undergoes the carbon–oxygen bond cleavage yielding radicals active in initiation of free radical polymerization chain.

    22. Dendrimers in thiol-ene crosslinked networks and the effect of subsequent generations on thermoset properties (pages 589–601)

      Camilla Nilsson, Eva Malmström, Mats Johansson and Stacy M. Trey

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23176

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      To investigate the effect of dendrimer generation on the properties of thiol-ene crosslinked films, four generations of allyl-ether functional dendrimers have been synthesized and combined with two commercially available trifunctional thiols, trimethylolpropane tri(3-mercaptopropanoate) (TRIS) and ethoxylated trimethylolpropane tri(3-mercaptopropanoate) (ETTMP). The photopolymerization was conducted without the addition of photoinitiator, resulting in two series of transparent and smooth films. Furthermore, all crosslinked films were characterized with respect to mechanical and thermal properties. It was found that homogeneous networks were formed and that both dendrimer generation and thiol functional moiety architecture had a significant effect on the resulting network properties.

    23. Photoinduced unzipping depolymerization of poly(olefin sulfone)s possessing photobase generator and base amplifier (pages 602–613)

      Takeo Sasaki and Hiroaki Yaguchi

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23179

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      The photoinduced depolymerization of poly(olefin sulfone)s was investigated. Poly(olefin sulfone)s possessing base-amplifying groups were synthesized. A photobase-generating compound was mixed with the poly(olefin sulfone)s and irradiated with 254 nm UV light. The decomposition ratio was significantly enhanced in poly(olefin sulfone)s that possessed base-amplifying groups. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    24. Novel well-defined glycopolymers synthesized via the reversible addition fragmentation chain transfer process in aqueous media (pages 614–627)

      Zhicheng Deng, Marya Ahmed and Ravin Narain

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23187

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      We describe here the direct synthesis of novel gluconamidoalkyl methacrylamides by reacting D-gluconolactone with aminoalkyl methacrylamides. The glycomonomers were then successfully polymerized via the reversible addition-fragmentation chain transfer process (RAFT) using 4-cyanopentanoic acid dithiobenzoate (CTP) as chain transfer agent and 4,4′-azobis(4-cyanovaleric acid) (ACVA) as the initiator in aqueous media.

    25. Synthesis of the four-arm star-block copolymer [PVC-b-PBA-CH(CH3)[BOND]CO[BOND]O[BOND]CH2]4C by SET-DTLRP initiated from a tetrafunctional initiator (pages 628–634)

      Virgil Percec and Monika J. Sienkowska

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23188

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      The four-arm star-block copolymer [PVC-b-PBA[BOND]CH(CH3)[BOND]CO[BOND]O[BOND]CH2]4C was synthesized by SET-DTLRP of VC in water initiated with tetrafunctional four-arm star poly(n-butyl acrylate) macroinitiator prepared similarly by SET-DTLRP using pentaerythritol tetrakis(2-iodopropionate) as tetrafunctional initiator. This block copolymer represents the first example of a star block-copolymer consisting of soft PBA and hard PVC segments. [Color figure can be viewed in the online issue, which is available at www.interscience.com.]

    26. Synthesis of α,ω-di(iodo)PVC and of four-arm star PVC with identical active chain ends by SET-DTLRP of VC initiated with bifunctional and tetrafunctional initiators (pages 635–652)

      Monika J. Sienkowska and Virgil Percec

      Article first published online: 11 DEC 2008 | DOI: 10.1002/pola.23189

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      α,ω-Di(iodo)PVC with two identical active chain ends and the four-arm star PVC with four identical active chain ends were synthesized by SET-DTLRP of VC initiated with the bifunctional initiators 1,2-bis(iodopropionyloxy)ethane, dimethyl 2,5-diiodohexanedioate, and bis(2-methoxyethyl)-2,5-diiodohexanedioate as well as the tetrafunctional initiator pentaerythritol tetrakis(2-iodopropionate). These PVCs provide suitable macroinitiators for further reinitiation and block copolymerization. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

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