Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 45 Issue 4

15 February 2007

Volume 45, Issue 4

Pages 553–708

  1. Highlights

    1. Top of page
    2. Highlights
    3. Articles
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      Fundamentals and development of high-efficiency supported catalyst systems for atom transfer radical polymerization (pages 553–565)

      Santiago Faucher and Shiping Zhu

      Article first published online: 3 JAN 2007 | DOI: 10.1002/pola.21785

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      The first generation solid-supported catalysts for atom transfer radical polymerization (ATRP) used tethered catalyst sites to mediate the deactivation process (top, right to left reaction). It is now understood, however, that these sites are incapable of mediating deactivation. The addition of soluble catalyst provides an alternate path for deactivation (bottom). Such hybrid ATRP catalysts (supported + soluble) are a promising route for high rate production of well-controlled polymers with low residual metal contents.

  2. Articles

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    2. Highlights
    3. Articles
    1. Direct polymerization of surface-tethered polyelectrolyte layers in aqueous solution via surface-confined atom transfer radical polymerization (pages 566–575)

      Amit Y. Sankhe, Scott M. Husson and S. Michael Kilbey II

      Article first published online: 9 JAN 2007 | DOI: 10.1002/pola.21817

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      Polyelectrolyte brushes were prepared directly by surface-confined atom transfer radical polymerization in aqueous solutions. Polyacid brushes were synthesized via a grafting-from approach with deprotonated monomers of methacrylic acid, sodium 4-styrene sulfonate, and itaconic acid. The addition of an alkali halide salt provided improved control in comparison with salt-free conditions and allowed polymer growth without cessation due to side reactions or catalyst deactivation. These features were reinforced by results from complementary kinetic modeling.

    2. Novel polymeric, thio-containing photoinitiator comprising in-chain benzophenone and an amine coinitiator for photopolymerization (pages 576–587)

      Jun Wei, Hongyu Wang and Jie Yin

      Article first published online: 4 JAN 2007 | DOI: 10.1002/pola.21818

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      Through the polycondensation of a novel thio-containing diamine, 4-amino-4′-[4-aminothiophenyl]benzophenone (AATBP), toluene-2,4-diisocyanate, and N-methyldiethanolamine (MDEA), we obtained a polymeric photoinitiator containing in-chain benzophenone, a thio group, and a tertiary amine in the same macromolecule (PUPIA). The ultraviolet–visible spectra indicated that PUPIA possessed maximal absorption similar to that of its low-molecular-weight counterpart (AATBP). Electron spin resonance analyses showed that PUPIA could generate free radicals efficiently. Differential scanning photocalorimetry studies indicated that PUPIA could efficiently initiate the photopolymerization of poly(propylene glycol)diacrylate and trimethylolpropane triacrylate. However, the photoinitiation systems of its low-molecular-weight counterparts (AATBP/MDEA or AATBP/PUPA) could hardly initiate the photopolymerization.

    3. AB and ABA type butyl acrylate and styrene block copolymers via RAFT-mediated miniemulsion polymerization (pages 588–604)

      A. Bowes, J. B. Mcleary and R. D. Sanderson

      Article first published online: 3 JAN 2007 | DOI: 10.1002/pola.21827

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      Two trithiocarbonate RAFT agents are compared in miniemulsion polymerization of styrene and butyl acrylate and the formation of seeded emulsion block copolymers. The choice of surfactant and block sequence is important in reducing the influence of terminated chains on the distributions of polymer that were obtained. ABA and AB type block copolymers were observed to form almost quantitatively when the surfactant and block sequence were correctly chosen. Stable latexes were obtained when the non-ionic surfactant, Brij®98, was used to polymerize butyl acrylate in RAFT-mediated miniemulsion polymerization. Both monofunctional (1) and difunctional (2) RAFT agents produced stable latexes under these conditions.

    4. Poly(ϵ-caprolactone)-b-poly(ethylene glycol)-b-poly(ϵ-caprolactone) triblock copolymers: Synthesis and self-assembly in aqueous solutions (pages 605–613)

      Yaqiong Zhang, Shengrong Guo, Chengfei Lu, Li Liu, Zonghai Li and Jianren Gu

      Article first published online: 3 JAN 2007 | DOI: 10.1002/pola.21739

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      Poly(ϵ-caprolactone)-b-poly(ethylene glycol)-b-poly(ϵ-caprolactone) triblock copolymers were synthesized by solution polymerization with poly(ethylene glycol) as a macromolecular initiator, and they were identified with 1H NMR and gel permeation chromatography. Self-assembly in aqueous solutions was investigated. The atomic force microscopy results showed that spherical micelles formed at the copolymer concentration of 2.5 × 10−4 g/mL, whereas necklacelike and wormlike shapes were adopted when the concentration was 0.25 g/mL, which was high enough to form a gel.

    5. Synthesis and polymerization of first-generation dendritic methacrylate macromonomers (pages 614–628)

      Sandra Reemers, Petra Mela, Ahmed Mourran, Sergei Magonov, Helmut Keul and Martin Möller

      Article first published online: 3 JAN 2007 | DOI: 10.1002/pola.21835

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      First-generation dendritic macromonomers with a methacryloyl end group on one side and long alkyl chains on the other side have been synthesized. Depending on the reaction conditions of the polymerization besides linear dendronized polymers, branched and crosslinked structures were obtained. Scanning force microscopy was performed on high molecular weight samples spincoated on highly oriented pyrolytic graphite to visualize the linear and branched dendronized polymers.

    6. Synthesis, hole mobility, and photovoltaic properties of two alternating poly[3-(hex-1-enyl)thiophene-co-thiophene]s (pages 629–638)

      Erjun Zhou, Zhan'ao Tan, Youjun He, Chunhe Yang and Yongfang Li

      Article first published online: 3 JAN 2007 | DOI: 10.1002/pola.21851

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      Two alternating poly[3-(hex-1-enyl)thiophene-co-thiophene]s, Pa (E:Z = 77:23) and Pb, were synthesized and compared with poly(3-hexylthiophene-co-thiophene) (P1) to study the effect of changing the carbon(α)–carbon(β) single bond into a carbon–carbon double bond on the properties of the polymers. Pa possessed the highest hole mobility of 7.02 × 10−4 cm2/V s (from the space-charge-limited current method), and the power conversion efficiencies of the polymer solar cell based on Pa reached 1.70%.

    7. Synthesis of new 1-decene-based LLDPE resins and comparison with the corresponding 1-octene- and 1-hexene-based LLDPE resins (pages 639–649)

      Han Hong, Zhicheng Zhang, T. C. M. Chung and R. W. Lee

      Article first published online: 3 JAN 2007 | DOI: 10.1002/pola.21825

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      Linear low density polyethylene (LLDPE) resins, containing 1-decene, 1-octene, and 1-hexene comonomers, were comparatively prepared by industrial CGC metallocene technology, under similar high temperature and high pressure condition. 1-Decene exhibits significantly higher incorporation than does 1-hexene and 1-octene, which may be due to its high boiling point. The resulting LLDPE copolymers show a clear structure–property relationship. Melting temperature and crystallinity are governed by mole % of comonomer, and the density is dependent on weight % of comonomer. The tensile properties of 1-decene-based LLDPE are very comparative with those of the commercial LLDPE resins.

    8. Synthesis and characterization of chiral polymer complexes incorporating polybinaphthyls, bipyridine, and Eu(III) (pages 650–660)

      Yixiang Cheng, Xiaowei Zou, Dan Zhu, Tingshun Zhu, Yan Liu, Shuwei Zhang and Hui Huang

      Article first published online: 4 JAN 2007 | DOI: 10.1002/pola.21766

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      Chiral conjugated polymers were synthesized through a Heck cross-coupling reaction, and chiral polymer complexes were obtained by bipyridyl moiety chelating coordination with Eu(TTA)3·2H2O (where TTA is 2-thenoyltrifluoroacetonate). The chiral polymer complexes could have not only polymer fluorescence but also the characteristic fluorescence of Eu(III) (5D0[RIGHTWARDS ARROW]7F2) at a different excited wavelength.

    9. Photosensitive polybenzoxazole based on a poly(o-hydroxy amide), a dissolution inhibitor, and a photoacid generator (pages 661–668)

      Tomohito Ogura and Mitsuru Ueda

      Article first published online: 8 JAN 2007 | DOI: 10.1002/pola.21855

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      A positive-type photosensitive polybenzoxazole (PSBO) based on a poly(o-hydroxyamide) (PHA), dissolution inhibitor (DI), 9,9-bis(4-tert-butoxycarbonyloxyphenyl)fluorene (t-Boc BHF), and the photoacid generator (PAG) (5-propylsulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl)acetonitrile (PTMA) has been developed. A clear positive image with 6-μm features and a 10-μm-thick pattern with high sensitivity and contrast were produced by contact-printing and converted into the poly(benzoxazole) patterns upon heating at 350°C for 1h.

    10. Synthesis and characterization of stimuli-sensitive micro- and nanohydrogels based on photocrosslinkable poly(dimethylaminoethyl methacrylate) (pages 669–679)

      Smrati Gupta, Dirk Kuckling, Katja Kretschmer, Veena Choudhary and Hans-Jürgen Adler

      Article first published online: 8 JAN 2007 | DOI: 10.1002/pola.21846

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      A versatile route was developed for the preparation of temperature- and pH-responsive hydrogels with small dimensions. Micro- and nanohydrogels of copolymers of N,N-dimethylaminoethyl methacrylate with various amounts (5 and 10 mol %) of dimethylmaleimidoethyl methacrylate were prepared by photocrosslinking. The hydrogels, prepared as thin layers as well as colloidal solutions, showed temperature- and pH-responsive behavior.

    11. Synthesis of macrocycles by the ring-crossover reaction of a cyclic dithioester (pages 680–687)

      Hiroto Kudo, Shinya Makino and Tadatomi Nishikubo

      Article first published online: 8 JAN 2007 | DOI: 10.1002/pola.21850

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      A cyclic polymer was synthesized by the ring-crossover reaction of a cyclic dithioester with a quaternary onium salt as a catalyst. Intermolecular and intramolecular thioester-exchange reactions occurred between the cyclic dithioester and resulting cyclic polymers under thermodynamic control, affording the corresponding cyclic polymer in a quantitative yield. [Color figure can be viewed in the online issue, which is available at]

    12. Preparation and characterization of poly(2-methacryloyloxyethyl phosphorylcholine)-block-poly(D,L-lactide) polymer nanoparticles (pages 688–698)

      Ging-Ho Hsiue, Chun-Liang Lo, Ching-Hao Cheng, Che-Ping Lin, Chun-Kai Huang and Hung-Hao Chen

      Article first published online: 8 JAN 2007 | DOI: 10.1002/pola.21741

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      A poly(D,L-lactide)–bromine macroinitiator was synthesized for use in the preparation of a novel biocompatible polymer. This amphiphilic diblock copolymer consisted of biodegradable poly(D,L-lactide) and 2-methacryloyloxyethyl phosphorylcholine and was formed by atom transfer radical polymerization. Polymeric nanoparticles were prepared by a dialysis process in a select solvent. The shape and structure of the polymeric nanoparticles were determined by 1H NMR, atomic force microscopy, and ζ-potential measurements. The results of cytotoxicity tests showed the good cytocompatibility of the lipid-like diblock copolymer poly(2-methacryloyloxyethyl phosphorylcholine)-block-poly(D,L-lactide).

    13. Novel route for synthesizing hyperbranched polyamine (pages 699–708)

      Jianhua Liu, Chun Ren, Zhu Yang and Wenfang Shi

      Article first published online: 10 JAN 2007 | DOI: 10.1002/pola.21839

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      A novel route for the synthesis of hyperbranched polyamine-containing imidazolidine rings was developed, proceeding by the step-growth polymerization of acrolein with ethylene diamine. Borohydride such as NaBH4 was used to reduce the imidazolidine group and open the ring for giving a stable hyperbranched polyamine. The reaction kinetics andpolymerization mechanism were studied with NMR and ultraviolet–visible spectroscopy. The molecular weights, degrees of branching, and glass-transition temperatures of the hyperbranched polyamines before and after reduction were compared.