Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Journal of Polymer Science Part A: Polymer Chemistry

1 November 2008

Volume 46, Issue 21

Pages 6983–7286

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      Recent advances in controlled/living radical polymerization in emulsion and dispersion (pages 6983–7001)

      Jung Kwon Oh

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23011

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      Conducting controlled/living radical polymerization (CRP) in emulsion media is more complicated and more challenging than its application in homogeneous bulk. These challenges come from the intrinsic kinetics of emulsion polymerization. Various approaches for conducting emulsion CRP have been developed, including controlled seeded emulsion polymerization, nanoprecipitation, use of short oligomers as macroinitiators for in situ block copolymerization, and RAFT-mediated self-assembly. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

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    1. Fully aromatic poly(ether ketone)s bearing macrocycle pendants: Synthesis and crosslinking (pages 7002–7010)

      Xigui Yue, Ming Zhu, Haibo Zhang, Baijun Liu, Yishan Wang and Zhenhua Jiang

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.22986

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      Aromatic poly(ether ketone)s bearing macrocycles were successfully prepared and could go crosslinking to form fully aromatic poly(ether ketone) thermosets via a ring-opening reaction. After crosslinking, these copolymers possessed high glass transition temperatures, excellent thermal stability, and attractive tensile properties. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]

    2. Initiation reactivity of anionic polymerization of fluorinated acrylates and methacrylates with diethyl(ethyl cyanoacetato)aluminum (pages 7011–7021)

      Youhei Umino, Tadashi Narita and Hiroshi Hamana

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23006

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      Pseudo-first-order rate constants of the reaction of diethyl(ethyl cyanoacetato)aluminum [(C2H5)2Al(NCCHCOOC2H5)] with 17 fluorinated acrylates and methacrylates and five hydrocarbon analogs for references were investigated to examine the initiation reactivities of the anionic polymerization of fluorinated vinyl monomers to afford the reactivity order: CH2[DOUBLE BOND]C(CF3)COOC2H5 > CH2[DOUBLE BOND]C(CF3)COOCH(CH3)2 > CH2[DOUBLE BOND]CHCOOCH2C6F5 > CH2[DOUBLE BOND]C(CF3)COOC(CH3)3 > CH2[DOUBLE BOND]C(CF3)COOCH2C6F5 > CH2[DOUBLE BOND]C(CF3)COOCH(CF3)2 ≥ CH2[DOUBLE BOND]CHCOOCH3 > CH2[DOUBLE BOND]CHCOOCH2C6H5 ≥ CH2[DOUBLE BOND]C (CF3)COOCH2CF3 > CH2[DOUBLE BOND]C(CH3)COOCH2C6F5 > CH2[DOUBLE BOND]CHCOOCH2CF3 > CH2[DOUBLE BOND]CHCOOCH2C2F5 > CH2[DOUBLE BOND]CHCOOCH(CF3)2 > CH2[DOUBLE BOND]C(CH3)COOCH3 > CH2[DOUBLE BOND]C(CH3)COOCH2C6H5 ≥ CH2[DOUBLE BOND]C(CH3)COOCH2CH2C8F17 > CH2[DOUBLE BOND]C(CH3)COOCH(CH3)2 > CH2[DOUBLE BOND]C(CH3)COOCH2C2F5 ≥ CH2[DOUBLE BOND]C(CH3)COOCH2CF3. No rate constants for CH2[DOUBLE BOND]C(CH3)COOCH(CF3)2, CH2[DOUBLE BOND]CFCOOC(CH3)3, and CH2[DOUBLE BOND]CFCOOCH2C2F5 were obtained because of too fast polymerization. The incorporation of a trifluoromethyl group into the vinyl group enhanced the reactivity toward the delocalized carbanion. The reactivity of other fluorinated acrylates and methacrylates was concluded to approximately be controlled by the fluorine contents and the bulkiness of substituents of monomers. The reactivity was generally decreased by increasing fluorine contents of monomers.

    3. Aliphatic poly(ester-carbonate)s bearing amino groups and its RGD peptide grafting (pages 7022–7032)

      Xiuli Hu, Xuesi Chen, Zhigang Xie, Haibo Cheng and Xiabin Jing

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23008

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      Ring-opening copolymerization of L-lactide (LA) and newly synthesized cyclic carbonate monomer (2-oxo[1,3]dioxan-5-yl)carbamic acid benzyl ester (CAB) containing protected amino groups leads to a random copolymer P(LA-co-CAB). The benzyloxycarbonyl (Cbz) protecting groups of the copolymer were successfully removed via catalytic hydrogenation to yield a poly(ester-carbonate) with primary amino groups. Further functionalization of the copolymer was demonstrated by grafting RGD peptide onto the pendant amino groups. RGD grafting improved cell affinity, showing enhanced cell adhesion, spreading, and proliferation. This amino-bearing and RGD-grafted copolymer is promising for cell or tissue engineering applications.

    4. Synthesis of amphiphilic multiblock and triblock copolymers of polydimethylsiloxane and poly(N,N-dimethylacrylamide) (pages 7033–7048)

      Dražen Pavlović, Jeffrey G. Linhardt, Jay F. Künzler and Devon A. Shipp

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23009

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      Using a combination of RAFT polymerization and polycondensation between diols/diamines and diacid chlorides, the synthesis and spectroscopic characterization of a new family of amphiphilic multiblock and triblock copolymers based on polydimethylsiloxane (PDMS) and poly(N,N-dimethylacrylamide) (PDMA) is described. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    5. Synthesis and self-assembly of tadpole-shaped organic/inorganic hybrid poly(N-isopropylacrylamide) containing polyhedral oligomeric silsesquioxane via RAFT polymerization (pages 7049–7061)

      Weian Zhang, Li Liu, Xiaodong Zhuang, Xiaohui Li, Jinrui Bai and Yu Chen

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23010

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      Tadpole-shaped organic/inorganic hybrid Poly(N-isopropylacrylamide) (PNIPAM) based on polyhedral oligomeric silsesquioxane (POSS) molecule was prepared using POSS-containing reversible addition-fragmentation transfer (RAFT) agent. The tadpole-shaped inorganic/organic hybrid PNIPAM can self-assemble into the micelle with POSS molecules as core and PNIPAM chains as shell in aqueous solution. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    6. Ethylene polymerization of the new titanium complexes bearing a phosphine oxide-bridged bisphenolato ligand (pages 7062–7073)

      Li-Peng He, Jing-Yu Liu, Li Pan and Yue-Sheng Li

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23012

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      A series of novel titanium complexes [O,P[DOUBLE BOND]O,O]TiCl2(thf) bearing a phosphine oxide-bridged bisphenolato ligand have been synthesized and characterized. Complex 6a was very robust and displayed notable catalytic activity for ethylene polymerization even at high temperature, affording high molecular weights polymers with unimodal distribution.

    7. Synthesis, photopolymerization and adhesive properties of new hydrolytically stable phosphonic acids for dental applications (pages 7074–7090)

      Yohann Catel, Michel Degrange, Loïc Le Pluart, Pierre-Jean Madec, Thi-Nhàn Pham and Luc Picton

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23013

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      New hydrolytically stable phosphonic acid monomers 4a–4c and 9 have been synthesized in good yields. Hydrolytic stability, free radical homopolymerizations, photopolymerization behavior with N,N′-diethyl-1,3-bis(acrylamido)propane as well as adhesive properties of these monomers have been investigated. Primers based on (N-methacrylamido) alkylphosphonic acids 4a–4c are able to generate a strong bond between the tooth substance and a composite.

    8. One-pot synthesis of star-block copolymers using double click reactions (pages 7091–7100)

      Hakan Durmaz, Aydan Dag, Alp Hizal, Gurkan Hizal and Umit Tunca

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23014

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      3-Arm star-block copolymers, (polystyrene-b-poly(methyl methacrylate))3, (PS-b-PMMA)3, and (polystyrene-b-poly(ethylene glycol))3, (PS-b-PEG)3, are prepared using double-click reactions: Huisgen and Diels–Alder, with a one-pot technique. PS and PMMA blocks with α-anthracene-ω-azide- and α-maleimide-end-groups, respectively, are achieved using suitable initiators in ATRP of St and MMA, respectively. However, PEG obtained from a commercial source is reacted with 3-acetyl-N-(2-hydroxyethyl)-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxamide (7) to give furan-protected maleimide-end-functionalized PEG. Finally, PS/PMMA and PS/PEG blocks are linked efficiently with trialkyne functional linking agent 1,1,1-tris[4-(2-propynyloxy)phenyl]-ethane (2) in order to give two samples of 3-arm star-block copolymers. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    9. High temperature resistant tailor-made poly(meth)acrylates bearing adamantyl group via atom transfer radical polymerization (pages 7101–7113)

      A. Amalin Kavitha and Nikhil K. Singha

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23015

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      Tailor-made poly(meth)acrylates bearing adamantyl group prepared via atom transfer radical polymerization. Incorporation of admantyl group led to the enhanced rate of polymerization, tremendously improved thermal stability, and raised the glass transition temperature of the poly(meth)acrylates, which can have several potential applications.

    10. Encapsulated clay particles in polystyrene by RAFT mediated miniemulsion polymerization (pages 7114–7126)

      Austin Samakande, Ronald D. Sanderson and Patrice C. Hartmann

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23016

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      RAFT-grafted Montmorillonite (MMT) clays, N,N-dimethyl-N-(4-(((phenylcarbonothioyl)thio)-methyl)benzyl)ethanammonium-MMT (PCDBAB-MMT) and N-(4-((((dodecyl-thio)carbonothioyl)thio)methyl)benzyl)-N,N-dimethylethanammo-nium-MMT (DCTBAB-MMT) were used for the synthesis of encapsulated polystyrene-clay nanocomposite (PS-CN) particles by free-radical polymerization in miniemulsion. The anchored RAFT agents were able to effectively control the polymerization process as was observed by the molar masses and PDIs of the polymer matrix that decreased with an increase in the RAFT-grafted clay concentration. TEM and SAXS analysis showed that the morphology of the PS-CNs changed from partially exfoliated at low clay loadings to intercalated as the clay loading increased. The thermo-mechanical properties of the nanocomposites were improved relative to those of the neat PS polymer, and were dependent on the morphology, clay loading and molar mass of the polymer matrix.

    11. Molecular design of outermost surface functionalized thermoresponsive polymeric micelles with biodegradable cores (pages 7127–7137)

      Jun Akimoto, Masamichi Nakayama, Kiyotaka Sakai and Teruo Okano

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23017

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      Surface functionalized thermoresponsive polymeric micelles are formed through multi-assemblies of end-functional thermoresponsive diblock copolymers. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    12. Libraries of methacrylic acid and oligo(ethylene glycol) methacrylate copolymers with LCST behavior (pages 7138–7147)

      C. Remzi Becer, Sabine Hahn, Martin W. M. Fijten, Hanneke M. L. Thijs, Richard Hoogenboom and Ulrich S. Schubert

      Version of Record online: 24 SEP 2008 | DOI: 10.1002/pola.23018

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      Several homopolymer and copolymer libraries of methacrylic acid and oligo(ethyleneglycol) methacrylate derivatives were prepared in an automated parallel synthesizer. The cloud points of the polymers were tuned from 20 to 90 °C by varying the comonomer content. Besides, dual-responsive poly (methacrylic acid)-r-(oligo(ethyleneglycol) methacrylate) were obtained that are revealing response to both temperature and pH value of the aqueous solution at certain monomer compositions. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    13. Synthesis and electroluminescent properties of fluorene-based copolymers containing electron-withdrawing thiazole derivatives (pages 7148–7161)

      In Hwan Jung, Young Kwan Jung, Jonghee Lee, Jong-Hwa Park, Han Young Woo, Jeong-Ik Lee, Hye Yong Chu and Hong-Ku Shim

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23019

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      We have synthesized fluorene-based copolymers containing the electron-withdrawing moieties thiazolothiazole and bithiazole. EL characteristics of PF-TBTT were found to be almost three times better than those of PF-TTZT. The lower LUMO energy of PF-TBTT enables easier electron injection from the cathode and results in much higher electroluminescence (EL) efficiency. Moreover, the nonplanar structure of PF-TBTT enhances the EL performance by suppressing the aggregation of the polymer chains.

    14. Synthesis and study of the thermal crosslinking of bis(m-aminophenyl) methylphosphine oxide based benzoxazine (pages 7162–7172)

      M. Spontón, M. S. Larrechi, J. C. Ronda, M. Galià and V. Cádiz

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23022

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      Bis(m-aminophenyl)methylphosphine oxide based benzoxazine (Bz-BAMPO) was obtained using a three-step synthetic method. The curing kinetics of Bz-BAMPO was investigated by nonisothermal differential scanning calorimetry (DSC) and by FTIR spectroscopy. The isoconversional method was used to evaluate the dependence of the effective activate energy on the extent of conversion. The evolving factor analysis (EFA) method was applied to the spectroscopic FTIR.

    15. Novel mesogen-jacketed poly(p-phenylenevinylene) derivatives bearing oxadiazole pendants: Design, synthesis, and optoelectronic properties (pages 7173–7186)

      Limei Sun, Ping Wang, Hao Jin, Xinghe Fan, Zhihao Shen, Xiaofang Chen and Qi-Feng Zhou

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23024

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      A series of novel poly(p-phenylenevinylene) derivatives with 1,3,4-oxadiazole moieties were designed and synthesized successfully by Horner-Witting-Emmons coupling reaction. All the polymers enjoy high thermal stability. PLEDs with the configuration of ITO/PEDOT/Polymer/TPBI(15 nm)/LiF(1 nm)/Al(100 nm) were fabricated, which emit a yellowish green light around 540 and 570 nm with a maximum brightness of 1074.7 cd/m2 and luminous efficiency of 0.108 cd/A. The introduction of the unique bulky OXD unit into PPVs at a low molar content largely improved the electroluminescence properties of PPV. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]

    16. “Click” coupling between alkyne-decorated multiwalled carbon nanotubes and reactive PDMA-PNIPAM micelles (pages 7187–7199)

      Jinyao Liu, Zhihua Nie, Yong Gao, Alex Adronov and Huaming Li

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23026

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      The Cu(I)-catalyzed [3 + 2] Huisgen cycloadditions between alkyne-decorated MWNTs and PDMA-PNIPAM diblock copolymer micelles with azide groups on the outer shell were performed in water under mild conditions. This “grafting to” method was demonstrated to generate nanotubes that were densely functionalized with high molecular weight polymers, which overcame the low graft density barrier that presented in the attachment of molecularly dissolved unimers of high molecular weight onto the MWNT surfaces. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    17. Synthesis of poly(tert-butyl acrylate-block-vinyl acetate) copolymers by combining ATRP and RAFT polymerizations (pages 7200–7206)

      Christy D. Petruczok, Richard F. Barlow and Devon A. Shipp

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23027

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      The synthesis of poly(tert-butyl acrylate-block-vinyl acetate) copolymers using a combination of atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization, is reported. The use of two methods is due to the disparity in reactivity of the two monomers, viz. vinyl acetate is difficult to polymerize via ATRP, and a suitable RAFT agent that can control the polymerization of vinyl acetate is typically unable to control the polymerization of tert-butyl acrylate.

    18. Stability and utility of pyridyl disulfide functionality in RAFT and conventional radical polymerizations (pages 7207–7224)

      Cyrille Boyer, Jingquan Liu, Lingjiun Wong, Michael Tippett, Volga Bulmus and Thomas P. Davis

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23028

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      Well-defined end-group functional polymers were synthesized in water by reversible addition fragmentation chain transfer (RAFT) polymerization using two different water-soluble RAFT agents. The pyridyldisulfide end-group functionality of polymers was found to be largely benign in free radical polymerizations, remaining intact for subsequent reaction with thiol groups. The utility of the pyridyl disulfide end-group functionality was demonstrated by conjugation of a model protein, BSA, to the polymers. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    19. Polyelectrolyte-grafted carbon nanotubes: Synthesis, reversible phase-transition behavior, and tribological properties as lubricant additives (pages 7225–7237)

      Xiaowei Pei, Yanqiu Xia, Weimin Liu, Bo Yu and Jingcheng Hao

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23029

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      Firstly, a solution of MWCNTs-g-PBIM-PF6 dispersed in propionitrile was added dropwise to a solution of tetrabutylammonium bromide salt in distilled water. The mixed solution was stirred and resulted in the complete transfer of MWCNTs-g-PILs from propionitrile layer to aqueous layer. Secondly, a solution of MWCNTs-g-PBIM-Br dispersed in distilled water was added dropwise to a solution of ammonium hexafluorophosphate salt in distilled water. The mixed solution was stirred and the homogeneous black solution became colorless, and black solids were precipitated. Finally, the MWCNTs-g-PBIM-PF6 was redispersed in propionitrile and the cycle of reversible phase-transition was constructed.

    20. Glycopolymers resulting from ethylene–vinyl alcohol copolymers: Synthetic approach, characterization, and interactions with lectins (pages 7238–7248)

      C. Ruiz, M. Sánchez-Chaves, M. L. Cerrada and M. Fernández-García

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23030

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      Novel glycopolymers based on ethylene-vinyl alcohol copolymers with potential application in the molecular recognition are prepared. A direct modification approach using phthalic anhydride is applied to easily obtain carbohydrate polymers without the requirement of further deprotection processes. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    21. Synthesis of homopolymers and copolymers containing an active ester of acrylic acid by RAFT: Scaffolds for controlling polyvalent ligand display (pages 7249–7257)

      Kunal V. Gujraty, Mallinamadugu J. Yanjarappa, Arundhati Saraph, Amit Joshi, Jeremy Mogridge and Ravi S. Kane

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23031

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      We have synthesized activated homopolymers of controlled molecular weight using the RAFT-based controlled radical polymerization of N-acryloyloxysuccinimide (NAS). The attachment of an inhibitory peptide to the activated polymer backbone yielded a potent controlled molecular weight polyvalent anthrax toxin inhibitor. We also used a semi-batch copolymerization method to control the placement of peptide-reactive NAS monomers along an inert backbone; subsequent functionalization with peptide yielded well-defined polyvalent anthrax toxin inhibitors that differed in their potencies. These strategies for controlling molecular weight, ligand density, and ligand placement will be broadly applicable for designing potent polyvalent inhibitors and for elucidating structure–activity relationships.

    22. Spontaneous crosslinking of poly(1,5-dioxepan-2-one) originating from ether bond fragmentation (pages 7258–7267)

      Anders Höglund and Ann-Christine Albertsson

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23037

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      Crosslinked poly(1,5-dioxepan-2-one) (PDXO) was obtained by the spontaneous reaction of unsaturated double bonds in the polymer chain. The double bonds were induced by thermal fragmentation of the ether bonds during synthesis, and this occurred when the synthesis temperature was 140 °C or higher. The water-soluble degradation products released during hydrolysis of the polymers were monitored by ESI-MS and MALDI-TOF-MS. Fragmentation of the ether bonds also occurred during the electrospray ionization. MALDI-TOF mass spectra showed water-soluble oligomers with a molar mass up to approximately 5000 g/mol but no fragmented species. Thermally induced ether bond fragmentation was shown to result in a crosslinked DXO polymer.

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    1. Pd/TPPMS in THF/water bi-phase mixture: Clean Suzuki coupling system to synthesis of high molecular weight polyfluorene derivative (pages 7268–7272)

      Changkun Liu, Amanda Repoley and Bing Zhou

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23021

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      Hydrosoluble ligand m-sulfonatophenyl-diphenylphosphine (TPPMS) was applied in Suzuki coupling reaction for synthesis of blue light-emitting polymer, poly[2,7-(9,9-dioctylfluorene)-co-N-(4-(3-methylpropyl)-diphenylaniline]. The polymer with a molecular weight as high as 230,000 and a molecular weight distribution of 1.28 was achieved due to the moderate solubility of TPPMS in both THF and water phase. The use of TPPMS ligand also helped to decrease the Pd residue in polymer product to levels below 10 ppm after only a single cycle of solid scavenger extraction.

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    1. Enhanced spin capturing polymerization: An efficient and versatile protocol for controlling molecular weight distributions (pages 7273–7279)

      Edgar H. H. Wong, Thomas Junkers and Christopher Barner-Kowollik

      Version of Record online: 26 SEP 2008 | DOI: 10.1002/pola.23025

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      An efficient and versatile polymerization protocol [enhanced spin capturing polymerization (ESCP)] is developed based on the enhanced capturing of macroradicals with a nitrone. It is demonstrated that nitrones employed at ambient and/or relatively low temperatures can efficiently control the molecular weight of the formed polymers in aqueous solution as well as in bulk. In addition, the facile formation of ABA triblock copolymers is feasible. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

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    1. Tracing arm-growth initiation in Z-RAFT star polymerization by NMR: The impact of the leaving R-group on star topology (pages 7280–7286)

      Daniel Boschmann, Martin Mänz, Ann-Christin Pöppler, Nicolai Sörensen and Philipp Vana

      Version of Record online: 25 SEP 2008 | DOI: 10.1002/pola.23032

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      Arm-growth initiation in six-armed Z-RAFT star polymerization of styrene-d8 was followed via the disappearance of 1H NMR signals of the leaving group at their original position. These measurements revealed a dramatic impact of the leaving group on star polymer topology. Phenylethyl as leaving group induced formation of completely initiated stars already after 8% of monomer conversion. Benzyl as leaving group, however, drastically slows down arm-growth initiation, resulting in fully initiated star polymers only after about 60% of monomer conversion. Below that value, star-polystyrene of the expected topology cannot be generated with benzyl as leaving group. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

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