Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 45 Issue 22

15 November 2007

Volume 45, Issue 22

Pages 5031–5370

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      Synthesis and biological application of glycopolymers (pages 5031–5036)

      Yoshiko Miura

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22369

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      Saccharides on the cell surfaces participate in a number of biochemical phenomena via the protein–saccharide interaction. Synthetic glycopolymers mimic the function of the cell-surface saccharides and efficiently interact with proteins, cells, and pathogens due to the multivalent effect. Since the biological functions are paid much attention, the glycopolymers are being increasingly explored as biofunctional materials for medicinal application and tissue engineering. This review presents a practical approach of glycopolymers. The glycopolymers were prepared by the facile syntheses of poly(vinyl saccharide)s and the physical and biological properties were introduced. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

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    1. Synthesis, characterization, and micellization of an epoxy-based amphiphilic diblock copolymer of ϵ-caprolactone and glycidyl methacrylate by enzymatic ring-opening polymerization and atom transfer radical polymerization (pages 5037–5049)

      Ke Sha, Dongshuang Li, Yapeng Li, Xiaotian Liu, Shuwei Wang, Jingqi Guan and Jingyuan Wang

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22000

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      The amphiphilic diblock copolymer polycaprolactone-block-poly(glycidyl methacrylate) was synthesized via enzymatic ring-opening polymerization and atom transfer radical polymerization (ATRP). A kinetic analysis of the ATRP of glycidyl methacrylate indicated a living/controlled radical process. The macromolecular structures, thermal properties, and self-assembly behaviors in aqueous solutions of the resulting copolymers were characterized by means of nuclear magnetic resonance, gel permeation chromatography, infrared spectroscopy, differential scanning calorimetry, wide-angle X-ray diffraction, dynamic light scattering, and transmission electron microscopy.

    2. Alternating copolymerization of carbon dioxide and propylene oxide catalyzed by (R, R)-SalenCoIII- (2,4-dinitrophenoxy) and Lewis-basic cocatalyst (pages 5050–5056)

      Yongsheng Niu, Wanxi Zhang, Xuan Pang, Xuesi Chen, Xiuli Zhuang and Xiabin Jing

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22244

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      The chiral (R,R)-SalenCoIII(2,4-dinitrophenoxy) (salen = N,N-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethylenediimine) was developed to synthesis the alternating copolymer of rac-PO/CO2 with the organic salt as a cocatalyst (4-dimethylamino)pyridine (DMAP). A linear carbonate linkage with almost 100% carbonate content and highly regioselectived polycarbonates via alternating copolymerzation of carbon dioxide were obtained. At an appropriate combination of all variables, high yield of turnover frequency (TOF) 501.2 h−1 and high molecular weight of 70,400 were achieved.

    3. Kinetic features of ethylene polymerization over supported catalysts [2,6-bis(imino)pyridyl iron dichloride/magnesium dichloride] with AlR3 as an activator (pages 5057–5066)

      Tatiana B. Mikenas, Vladimir A. Zakharov, Lyudmila G. Echevskaya and Mikhail A. Matsko

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22245

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      Data presented on the effect of ethylene and hydrogen concentration, polymerization duration and α-olefin addition on the activity, molecular weigh distribution, and molecular structures of polymers give ground to propose the scheme of catalyst deactivation via the formation of π-allyl complexes and its hydrogenation by hydrogen (reactivation).

    4. Copolymerizations of butyl methacrylate and fluorinated methacrylates via RAFT miniemulsion polymerization (pages 5067–5075)

      Tian-Ying Guo, Donglin Tang, Moudao Song and Banghua Zhang

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22249

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      Copolymerizations of n-butyl methacrylate (BMA) and fluoro-methacrylates were carried out via reversible addition-fragmentation chain transfer miniemulsion polymerization, using cumyl dithiobenzoate as a chain transfer agent. The reactivity ratios of BMA and fluoromethacrylate in this kind of polymerization system were investigated by SEC and NMR, from which the Q- and e-values of HFBMA and TFEMA were calculated. The thermal property and the wetting property of copolymers were also discussed. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    5. Synthesis, characterization, and thermal degradation mechanism of fast biodegradable PPSu/PCL copolymers (pages 5076–5090)

      S. Papadimitriou, D. N. Bikiaris, K. Chrissafis, K. M. Paraskevopoulos and S. Mourtas

      Version of Record online: 3 OCT 2007 | DOI: 10.1002/pola.22250

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      Fast biodegradable PPSu/PCL random copolymers with very high molecular weights were prepared at different weight ratios using a combination of polycondensation and ring opening polymerisation of ε-CL. The copolymers have satisfactory tensile strength and very high elongation at break while their thermal stabilities are very high. Enzymatic hydrolysis at pH 7.2 with Rhizopus delemar lipase and Pseudomonas Cepacia lipase revealed that the biodegradation rates of the copolymers are very high compared with that of neat PCL and increases by increasing the PPSu content. The particular copolymers after 12 days of enzymatic hydrolysis degraded completely.

    6. Highly efficient and well-controlled ambient temperature RAFT polymerization of glycidyl methacrylate under visible light radiation (pages 5091–5102)

      Huiwen Yin, Haimei Zheng, Lican Lu, Pengsheng Liu and Yuanli Cai

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22251

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      Well-defined poly(glycidyl methacrylate) (PGMA) polymers and their corresponding block copolymers were synthesized via highly efficient and well-controlled 2-cyanoprop-2-yl(4-fluoro) dithiobenzoate or CPFDB-mediated ambient temperature RAFT polymerization under environmentally friendly visible light radiation (λ = 405–577 nm), using a (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TPO) photoinitiator. More importantly, under visible light radiation, a relatively high initial molar ratio of GMA to CPFDB and TPO led to shortening the initialization period of RAFT process and accelerating the overall polymerization rate, thus in favor of the synthesis of well-defined PGMA polymers and PGMA-based block copolymers with high molecular weights.

    7. Thiourethane-based thiol-ene high Tg networks: Preparation, thermal, mechanical, and physical properties (pages 5103–5111)

      Qin Li, Hui Zhou, Douglas A. Wicks and Charles E. Hoyle

      Version of Record online: 3 OCT 2007 | DOI: 10.1002/pola.22252

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      This paper deals with the synthesis of multifunctional thiols based upon aliphatic and aromatic urethanes and their use as comonomers in the thiol-ene polymerization (a combination of photopolymerization and thermal polymerization) with a Triallyl Triazine. The glass transitions of the networks are >120 °C, much higher than ever reported for any thiol-ene-based system, and the tan δ peaks are very narrow. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    8. Synthesis of linear and hyperbranched poly(etherketone)s containing flexible oxyethylene spacers (pages 5112–5122)

      In-Yup Jeon, Loon-Seng Tan and Jong-Beom Baek

      Version of Record online: 3 OCT 2007 | DOI: 10.1002/pola.22253

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      Linear and hyperbranched poly(etherketone)s containing flexible oxyethylene spacers were synthesized via direct Friedel–Crafts reaction as a polymer-forming reaction. Thus, two self-polymerizable AB monomers, 4-(2-phenoxyethoxy)benzoic acid and 3-(2-phenoxyethoxy)benzoic acid, and an AB2 monomer, 3,5-bis(2-phenoxyethoxy)benzoic acid were prepared and polymerized in the reaction medium, polyphosphoric acid (PPA)/phosphorous pentoxide (P2O5), which was strong enough to drive the reaction directly from carboxylic acid instead of carboxylic acid chloride to afford corresponding high molecular weight polymers.

    9. Water-soluble conjugated polymers: Synthesis and optical properties (pages 5123–5135)

      Baohan Xie, Mahuya Bagui, Ruirun Guo, Kun Li, Qing Wang and Zhonghua Peng

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22254

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      Two sets of water-soluble poly(phenylene vinylene)s carrying sulphonate pendants and alkoxy side chains were prepared. Set I polymers, having the methoxy substituents, aggregate much more strongly than the longer triglyme side chain-containing set II polymers, leading to dramatically different morphological and optical properties for the two sets of polymers. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    10. Synthesis of novel asymmetric dendritic-linear-dendritic block copolymers via “living” anionic polymerization of ethylene oxide initiated by dendritic macroinitiators (pages 5136–5148)

      Ivan Gitsov, Arsen Simonyan and Nikolay G. Vladimirov

      Version of Record online: 3 OCT 2007 | DOI: 10.1002/pola.22258

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      A new class of dendritic-linear dendritic copolymers with asymmetric macromolecular architecture is formed by living anionic polymerization of ethylene oxide. The resulting hybrids show peculiar self-assembling pattern in block-selective media.

    11. Synthesis and self-assembly behavior study of α,ω-dicarboxyl-poly(ethylene glycol)–permethyl-6-amino-6-deoxy-β-cyclodextrin-monoamide: A new β-cyclodextrin conjugate (pages 5149–5155)

      Miklós Nagy, László Szőllősi, Sándor Kéki, Pál Herczegh, Gyula Batta, László Jicsinszky and Miklós Zsuga

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22259

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      A new type of amphiphilic macromolecule was synthesized through the attachment of a poly(ethylene glycol) chain to a permethyl-amino-β-cyclodextrin ring. The presence of supramolecular structures in aqueous media was detected with dynamic light scattering and proven also by 2D NOESY and DOSY experiments. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    12. Preparation of poly(styrene-b-N-isopropylacrylamide) micelles surface-linked with gold nanoparticles and thermo-responsive ultraviolet–visible absorbance (pages 5156–5163)

      Jian Li, Wei-Dong He and Xiao-Li Sun

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22260

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      Thiol-terminated poly(styrene-b-N-isopropylacrylamide) (PSt-b-PNIPAM-SH) was synthesized through reversible addition-fragmentation-transfer polymerization and used to prepare its core/shell micelles surface-linked with gold nanoparticles (PSt-b-PNIPAM-Au). The number of gold nanoparticles per micelle depended on the molar ratio of HAuCl4 to thiol group of PSt-b-PNIPAM-SH. The micelles exhibited thermo-responsive behavior, allowing for the reversible modulation of the distance between gold nanoparticles and UV–vis absorbance of PSt-b-PNIPAM-Au.

    13. Miktoarm star copolymers of poly(ϵ-caprolactone) from a novel heterofunctional initiator (pages 5164–5181)

      Dimitrios Priftis, Marinos Pitsikalis and Nikos Hadjichristidis

      Version of Record online: 3 OCT 2007 | DOI: 10.1002/pola.22261

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      A novel heterofunctional initiator with two ring opening polymerization (ROP) and two atom transfer radical polymerization (ATRP) initiating sites, was used to prepare A2B2 miktoarm star copolymers of poly(ϵ-caprolactone), PεCL, with polystyrene, PS, poly(methyl methacrylate), PMMA, poly(dimethylaminoethyl methacrylate), PDMAEMA, and poly(2-hydroxyethyl methacrylate), PHEMA. A2B miktoarm stars, A being PεCL or poly(δ-valerolactone), PδVL and B PS were also prepared from ω,ω-dihydroxy-PS, synthesized from ω–Br-PS and serinol, by ROP of ϵCL or δVL. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    14. Click chemistry in materials synthesis. III. Metal-adhesive polymers from Cu(I)-catalyzed azide–alkyne cycloaddition (pages 5182–5189)

      Yi Liu, David D. Díaz, Adrian A. Accurso, K. Barry Sharpless, Valery V. Fokin and M. G. Finn

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22262

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      Mixtures of polyvalent azides and alkynes in contact with metallic copper surfaces produce metal-adhesive crosslinked polymers. The process can be speeded by the addition of copper salts to increase the concentration of catalytic Cu(I) ions. The strength of these materials was assayed in a peel test, leading to the discovery of the triazide + tetra-alkyne mixture shown here as the most effective combination identified to date. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    15. Effect of the terminal substituent of azobenzene on the properties of ABA triblock copolymers via atom transfer radical polymerization (pages 5190–5198)

      Xinde Tang, Longcheng Gao, Xinghe Fan and Qifeng Zhou

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22263

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      The effect of the terminal substituent of azobenzene on the properties of ABA triblock copolymers was investigated. For this study, three kinds of azobenzene-containing monomers with different terminal substituents were used to synthesize ABA triblock copolymers by atom transfer radical polymerization. These copolymers exhibited controlled molecular weights and narrow molecular weight distributions and showed liquid-crystalline properties. PMMAzo25–PEG13–PMMAzo25 and PMMAzo12–PEG13–PMMAzo12 had a smectic mesophase and a nematic mesophase, whereas both PEMAzo14–PEG13–PEMAzo14 and PNMAzo14–PEG13–PNMAzo14 had a nematic mesophase (PMMAzo is poly{6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate}, PEMAzo is poly{6-[4-(4-ethoxyphenylazo)phenoxy]hexyl methacrylate}, and PNMAzo is poly{6-[4-(4-nitrophenylazo)phenoxy]hexyl methacrylate}). The liquid-crystalline properties of these copolymers highly depended on the terminal substituent of azobenzene. The photoresponsive behavior of these copolymers was also investigated in tetrahydrofuran solutions, and the influence of the terminal substituents attached to azobenzene was studied.

    16. Ethylene polymerization and copolymerization with 10-undecen-1-ol using the catalyst system DADNi(NCS)2/MAO (pages 5199–5208)

      Carlos L. P. Carone, Geraldo L. Crossetti, Nara R. S. Basso, Álvaro G. O. Moraes, João H. Z. dos Santos, Rubens Bisatto and Griselda B. Galland

      Version of Record online: 4 OCT 2007 | DOI: 10.1002/pola.22264

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      The catalyst DADNi(NCS)2 (DAD = (ArN[DOUBLE BOND]C(Me)[BOND]C(Me)[DOUBLE BOND] ArN); Ar = 2,6-C6H3), activated by methylaluminoxane, was shown to be active in ethylene polymerization, even at 80 °C and when supported on silica. The catalyst system was also tested in ethylene and 10-undecen-1-ol copolymerization at different ethylene pressures. The polar monomer protected by triisopropylaluminum was incorporated into the polymer chain. According to 13C-NMR analyses, all the resulting polyethylenes were shown to be highly branched and the polar monomer incorporation decreased as ethylene pressure increased.

    17. Organoaluminum-mediated polymerization of diazoketones (pages 5209–5214)

      Eiji Ihara, Masami Kida, Tomomichi Itoh and Kenzo Inoue

      Version of Record online: 2 OCT 2007 | DOI: 10.1002/pola.22266

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      Polymerization of diazoketones mediated by organoaluminum compounds was investigated. Trialkylaluminum R3Al (R = iBu, Et, Me) and diisobutylaluminum hydride (DIBAL) polymerized (E)-1-diazo-3-nonen-2-one (1) to give polymers with Mn = 2000–3500, which contained nearly 33 mol % of azo group ([BOND]N[DOUBLE BOND]N[BOND]) along with the dominant acylmethylene unit in the main chain. On the other hand, when (E)-1-diazo-4-phenyl-3-buten-2-one (2) was used as a monomer for the organoaluminum-mediated polymerization, the resulting polymers had ethylidene ([BOND]CH[CH3][BOND]) units in the main chain along with acylmethylene and azo group, as a result of reductive cleavage of the acyl group during the polymerization.

    18. Melt grafting of polymethyl methacrylate onto poly(ethylene-co-1-octene) by reactive extrusion: Model compound approach (pages 5215–5226)

      Thierry Badel, Emmanuel Beyou, Veronique Bounor-Legaré, Philippe Chaumont, Jean Jacques Flat and Alain Michel

      Version of Record online: 4 OCT 2007 | DOI: 10.1002/pola.22267

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      We studied the chemical modification of molten polyolefins with methyl methacrylate (MMA) by a free radical in situ polymerization in bulk at 150 and 170 °C with model compounds. The process is based on a radical grafting reaction between peroxide-derived alkoxyl radicals, methyl methacrylate and low-molecular weight hydrocarbons substrates (RH). From 150 to 170 °C, a depropagation reaction occurs so that chain molecular weight and monomer conversion decrease. The formation of methyl initiated PMMA and PMMA grafted alkane is evidenced by MALDI-TOF spectroscopy.

    19. Amphiphilic PEG/alkyl-grafted comb polylactides (pages 5227–5236)

      Xuwei Jiang, Erin B. Vogel, Milton R. Smith III and Gregory L. Baker

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22268

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      Polylactides that have one hydrophobic C16 alkyl chain and one hydrophilic triethylene glycol segment per repeat unit were synthesized. These amphiphilic polymers form ∼ 20-nm micelles in solution and are capable of encapsulating hydrophobic guests. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    20. Novel multiblock-co-ionomers as potential polymer electrolyte membrane materials (pages 5237–5255)

      Frank Schönberger and Jochen Kerres

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22269

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      Structure–property relationships have been made for a series of novel multiblock-co-ionomers consisting of sulfonated and partially fluorinated domains. Beside the structural investigation of the corresponding telechelic macromonomers and the multiblock-co-ionomers by NMR spectroscopy and gel permeation chromatographiy membrane properties of this series were comparatively investigated. The incorporation of hexafluoroisopropylidene as linkage group in the hydrophilic domains revealed to be advantageous over the other investigated groups in terms their properties relevant for possible fuel cell applications.

    21. Synthesis and characterization of a biodegradable amphiphilic copolymer based on branched poly(ϵ-caprolactone) and poly(ethylene glycol) (pages 5256–5265)

      Tao Zou, Song-Lin Li, Xian-Zheng Zhang, Xiao-Jun Wu, Si-Xue Cheng and Ren-Xi Zhuo

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22270

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      A novel biodegradable amphiphilic copolymer with hydrophobic poly(ε-caprolactone) branches containing cholic acid moiety and a hydrophilic poly(ethylene glycol) chain was synthesized. The amphiphilic copolymer could self-assemble into micelles to encapsulate drugs in an aqueous solution. Due to the branched structure of the hydrophobic part of the copolymer and the relatively fast degradation rate of the copolymer, an improved drug release behavior was observed. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    22. Synthesis, characterization, and photovoltaic properties of novel conjugated copolymers derived from phenothiazines (pages 5266–5276)

      Weihua Tang, Thomas Kietzke, Pardhasaradhi Vemulamada and Zhi-Kuan Chen

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22271

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      Two novel series of phenothiazine-based copolymers were synthesized using Suzuki coupling reaction, with their structures as well as physical and photovoltaic properties characterized. The polymers exhibited good thermal stability (temperature at 5% weight loss ∼ 342–390 °C) and high glass transition temperatures (Tg = 126–150 °C). As high 0.24% power conversion efficiency was obtained for the solar cells fabricated using blends of the copolymers and [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) in a 1:1 weight ratio. Open circuit voltages of up to 0.8 V have been obtained.

    23. Synthesis and characterization of poly(benzodithiophene) derivative for organic thin film transistors (pages 5277–5284)

      Thi Tuyet Mai Dang, Sung-Jin Park, Jong-Won Park, Dae-Sung Chung, Chan Eon Park, Yun-Hi Kim and Soon-Ki Kwon

      Version of Record online: 4 OCT 2007 | DOI: 10.1002/pola.22272

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      A new poly(benzodithiophene) derivative was designed, synthesized, and characterized. The polymer has very good solubility in organic solvents and good thermal stability with Tg of 164 °C. The polymer shows UV-optical absorption at 406 nm, photoluminescence spectroscopy at 504 nm in a film, and oxidative potential with HOMO level of −5.71 eV. A solution-processed polymer thin film transistor device shows a mobility of 3 × 10−5 to 8 × 10−5 cm2 V−1 s−1, and an on/off current ratio of 104.

    24. Developing a hybrid emulsion polymerization system to synthesize Fe3O4/polystyrene latexes with narrow size distribution and high magnetite content (pages 5285–5295)

      Longlan Cui, Hong Xu, Ping He, Keiko Sumitomo, Yoshinori Yamaguchi and Hongchen Gu

      Version of Record online: 2 OCT 2007 | DOI: 10.1002/pola.22273

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      We report a hybrid emulsion polymerization system for synthesizing Fe3O4/polystyrene composite latex with narrow size distribution and high magnetite content. This system involves binary droplets of magnetite droplets with a diameter of 100–200 nm and styrene droplets with a diameter of 3–4 μm. With extremely low surfactants concentration (≪CMC), the nucleated loci are selectively controlled in the Mag-droplets as the result of smaller droplet size and larger surface ratio, while the St-droplets serve as monomer reservoirs. By this method, Fe3O4/polystyrene latexes with narrow size distribution, high magnetite content up to 86 wt %, and various composite morphology were obtained.

    25. Synthesis and characterization of hyperbranched polyfluorenes containing triarylpyrazoline cores towards efficient blue light-emitting diodes (pages 5296–5307)

      Qiang Peng, Liushui Yan, Dezhi Chen, Fuzhi Wang, Ping Wang and Dechun Zou

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22274

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      New series of hyperbranched polyfluorenes containing triarylpyrazoline cores have been synthesized according to the “A2 + A2 + B3” Suzuki coupling method. The long-wavelength emission of polyfluorenes had been effectively reduced in the hyperbranched polymers. The three-layer device based on PFNZ10 emitted pure blue light with a low turn-on voltage of 5.3 V and a maximum external quantum efficiency of about 1.93%.

    26. Preparation, Tg improvement, and thermal stability enhancement mechanism of soluble poly(methyl methacrylate) nanocomposites by incorporating octavinyl polyhedral oligomeric silsesquioxanes (pages 5308–5317)

      Hongyao Xu, Benhong Yang, Jiafeng Wang, Shanyi Guang and Cun Li

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22275

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      The soluble PMMA–POSS hybrid nanocomposites containing octavinyl-polyhedral oligomeric silsesquioxane were successfully prepared by free radical copolymerization method. POSS content in these hybrid composites can be effectively controlled by varying the feed ratio of POSS. The DSC and TGA results show that the resultant hybrid nanocomposites have higher Tg and better thermal stability than the control PMMA homopolymer. The Tg increase is attributed to the dual contributions of the molecular motion hindrance from the bulky POSS cores and the dipole–dipole interaction between PMMA and POSS cores. The thermal stability enhancement is mainly attributed to the incorporation of nanoscale inorganic POSS uniformly dispersed at molecular level.

    27. Synthesis of amphiphilic and thermosensitive graft copolymers with fluorescence P(St-co-(p-CMS))-g-PNIPAAM by combination of NMP and RAFT methods (pages 5318–5328)

      Sumei Wang, Zhenping Cheng, Jian Zhu, Zhengbiao Zhang and Xiulin Zhu

      Version of Record online: 4 OCT 2007 | DOI: 10.1002/pola.22277

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      Poly(styrene-co-(p-chloromethylstyrene))-g-poly(N-isopropylacrylamide) and (P(St-co-(p-CMS))-g-PNIPAAM) were successfully prepared by three-step process. Firstly, we synthesized the random copolymers of P(St-co-(p-CMS)) via the NMP of St and p-CMS. Secondly, the P(St-co-(p-CMS)) copolymers were converted into macro-RAFT agents with fluorescent carbazole as Z-group. Thirdly, the macro-RAFT agents were used in the RAFT polymerization of NIPAAM to prepare amphiphilic and thermosensitive graft copolymers with fluorescence P(St-co-(p-CMS))-g-PNIPAAM with controlled molecular weights and well-defined structures.

    28. PS/PMMA mixed polymer brushes on the surface of clay layers: Preparation and application in polymer blends (pages 5329–5338)

      Jian Zhang, Yongfang Yang, Chuanzhuang Zhao and Hanying Zhao

      Version of Record online: 4 OCT 2007 | DOI: 10.1002/pola.22278

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      Free radical initiator molecules with quaternary ammonium end groups were intercalated into the interlayer spacing of clay layers. PS/PMMA mixed polymer brushes were prepared on the surface of clay layers by in situ free radical polymerization. Intercalated structure and exfoliated structure could be found in the nanocomposites. The application of nanocomposites in compatibilization of immiscible PS/PMMA blends was investigated.

    29. Synthesis and structural characterization of syndiotactic trans-1,2 and cis-1,2 polyhexadienes (pages 5339–5353)

      Giovanni Ricci, Aldo Boglia, Tiziano Motta, Fabio Bertini, Antonella Caterina Boccia, Lucia Zetta, Enrica Alberti, Antonino Famulari, Paolo Arosio and Stefano Valdo Meille

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22279

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      Two novel polymers, syndiotactic trans-1,2 polyhexadiene and syndiotactic cis-1,2 polyhexadiene, were obtained by polymerizing respectively the E isomer and the Z isomer of 1,3-hexadiene with the systems CoCl2(PiPrPh2)2-MAO and CpTiCl3-MAO. Both polymers were fully characterized by IR, NMR, GPC, and DSC techniques; in case of the crystalline trans polymer, molecular mechanics calculations were carried out and structural models consistent with the X-ray diffraction data were proposed.

    30. Synthesis and characterization of well-defined, amphiphilic poly(N-isopropylacrylamide)- b-[2-hydroxyethyl methacrylate-poly(ϵ-caprolactone)]n graft copolymers by RAFT polymerization and macromonomer method (pages 5354–5364)

      Jing-Ling Zhu, Xian-Zheng Zhang, Han Cheng, Yong-Yong Li, Si-Xue Cheng and Ren-Xi Zhuo

      Version of Record online: 1 OCT 2007 | DOI: 10.1002/pola.22280

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      Well-defined poly(N-isopropylacrylamide)-b-[2-hydroxyethyl methacrylate-poly(ε-caprolactone)]n (PNIPAAm-b-(HEMA-PCL)n) (n = 3 or 9) graft copolymers were synthesized by RAFT polymerization and macromonomer method. Transmission electron microscopy shows that the micelles exhibit a nanosized spherical morphology within a size range of 30–100 nm. The paclitaxel-loaded PNIPAAm-b-(HEMA-PCL)3 micelles show temperature-stimulated controlled release, which would find great potential as smart drug carriers.

  3. Rapid Communications

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    3. Articles
    4. Rapid Communications
    1. Phosgene-free synthesis of N-carboxyanhydrides of α-amino acids based on bisarylcarbonates as starting compounds (pages 5365–5370)

      Yukihiro Fujita, Koichi Koga, Hyun-Kyoung Kim, Xiao-Shui Wang, Atsushi Sudo, Haruo Nishida and Takeshi Endo

      Version of Record online: 4 OCT 2007 | DOI: 10.1002/pola.22281

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      A new convenient access to N-carboxyanhydride (NCA) monomers has been achieved based on the utilization of bisarylcarbonates as a carbonyl source, which are activated by electron-withdrawing substituents on their aryl groups such as fluorine atom and nitro group. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

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