Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 45 Issue 17

1 September 2007

Volume 45, Issue 17

Pages 3803–4183

  1. Highlights

    1. Top of page
    2. Highlights
    3. Articles
    4. Rapid Communications
    5. Notes
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      Arborescent polymers and other dendrigraft polymers: A journey into structural diversity (pages 3803–3810)

      Mario Gauthier

      Article first published online: 5 JUL 2007 | DOI: 10.1002/pola.22242

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      Arborescent polymers are a family of dendritic macromolecules derived from successive grafting reactions of polymer segments in a generation-based scheme analogous to dendrimer syntheses. These branched molecules display some of the properties and characteristics typical of other dendritic polymers, in spite of their much larger size. An overview of the historical aspects of the synthesis of arborescent polymers and related structures is provided, including more recent developments in the field.

  2. Articles

    1. Top of page
    2. Highlights
    3. Articles
    4. Rapid Communications
    5. Notes
    1. Novel polymer monolith prepared from a water-soluble crosslinking agent (pages 3811–3817)

      Takuya Kubo, Naomi Kimura, Ken Hosoya and Kunimitsu Kaya

      Article first published online: 5 JUL 2007 | DOI: 10.1002/pola.22130

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      We described the fundamental properties of novel polymer monoliths that were prepared from a water-soluble crosslinking agent. Each monolith was evaluated by scanning electron microscope (SEM) and scanning probe microscope (SPM) to observe the monolithic structure. As results of evaluations, SEM evaluations suggested that polymer porogenic solvent (PEG) was contributed to the construction of monolithic structure, and the polymerization degree of PEG was also taken effect of the structural changing by the variation of phase separation. Additionally, the results of SPM evaluations and the differences of monolithic structure were also reflected under water condition although the swelling of polymer was observed. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    2. Grafting of methacrylates and styrene on to polystyrene backbone via a “grafting from” ATRP process at ambient temperature (pages 3818–3832)

      A. V. Vivek and R. Dhamodharan

      Article first published online: 5 JUL 2007 | DOI: 10.1002/pola.22131

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      Well defined graft copolymers are prepared by “grafting from” ATRP at room temperature (30 °C). The experiments were aimed at grafting methacrylates and styrene at latent initiating sites of polystyrene. Graft copolymerization followed by block polymerization enabled the synthesis of highly branched polymer brush, in which the grafting density can be adjusted by appropriate choice of bromide concentration in the polystyrene backbone. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    3. Synthesis, characterization, and influence of synthesis parameters on particle sizes of a new microgel family (pages 3833–3842)

      Virginia Sáez Martínez, Leyre Pérez Álvarez, Estíbaliz Hernáez, Teresa Herrero and Issa Katime

      Article first published online: 5 JUL 2007 | DOI: 10.1002/pola.22133

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      Precipitation polymerization is an easy method to obtain monodisperse nanometric crosslinked microgels. Poly(NPA-co-MeAM) and poly(NPA-co-NIPA) reactive microgels were synthesized by this method. These microgels are able to form colloidally stable dispersions. SEM micrographs (see Figure) show strictly spherical particles with a moderate polydispersity. The particle size distributions measured by light scattering ranged from 100 to 600 nm. It is important to notice that several synthetic parameters can affect the particle size of these materials and thus, indirectly, their properties and future applications. One of these parameters is the crosslinking density (see Figure): it limits microgel swelling and thus, the particle sizes, but an excess of crosslinker content can increase the physical dimensions of the dry microgels, which can be relevant in the final particle sizes of the swollen microgels, even more than the decrease in the swelling capacity.

    4. Kinetics of radical copolymerization of [1-(fluoromethyl)vinyl]benzene with chlorotrifluoroethylene (pages 3843–3850)

      G. Kostov, M. Tredwell, V. Gouverneur and B. Ameduri

      Article first published online: 5 JUL 2007 | DOI: 10.1002/pola.22134

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      The synthesis of [1-(fluoromethyl)vinyl]benzene and its radical copolymerization with chlorotrifluorethylene initiated by tert-butyl peroxypivalate are presented. The kinetics of that copolymerization led to the determination of the reactivity ratios of both comonomers.

    5. Thermal polycondensation of sugar fluoride to form highly branched polysaccharide (pages 3851–3860)

      Atsushi Kanazawa, Shingo Namiki and Masato Suzuki

      Article first published online: 18 JUL 2007 | DOI: 10.1002/pola.22135

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      Various sugar fluorides were found to undergo powder-to-powder polycondensation without any catalyst at 110–160 °C under vacuum, giving highly branched polysaccharides (Conv. = 40–95%, Mw = 1400–20,000). The cross-polarized optical microscopy at 110 °C disclosed that the crystal shape of α-glucosyl fluoride was unchanged throughout the polymerization in spite of producing the amorphous polymer. Interestingly, α-maltosyl fluoride hydrate was polymerized at the lower temperature (100 °C) than the anhydrate, which required 160 °C for the polymerization. They produced different structure polymers even from the same monomer. The polymer from the former consisted of the disaccharide-repeating unit, while the repeating unit of the polymer from the latter was the monosaccharide, which was formed by the acetal exchange reaction. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    6. Alternating copolymers of electron-rich arylamine and electron-deficient 2,1,3-benzothiadiazole: Synthesis, characterization and photovoltaic properties (pages 3861–3871)

      Lijun Huo, Chang He, Minfang Han, Erjun Zhou and Yongfang Li

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22136

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      A series of alternating copolymers of electron-rich arylamine and electron-deficient 2,1,3-benzothiadiazole (BT) were synthesized for getting low bandgap conjugated polymers with higher hole mobility. The hole mobility of TP-BT film reached 4.68 × 10−5 cm2/Vs, and the power conversion efficiency of the polymer solar cell based on TP-BT as donor and PCBM as acceptor reached 0.52% under the illumination of AM 1.5, 100 mW/cm2, indicating that TP-BT is a promising photovoltaic material.

    7. Control of molecular weight in polymerization of vinyl chloride with Cp*Ti(OPh)3/MAO catalyst (pages 3872–3876)

      Kiyoshi Endo, Tsuyoshi Nomaguchi and Yoshikatsu Tsuchiya

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22137

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      Polymerization of vinyl chloride (VC) with titanium complexes containing Ti-OPh bond in combination with methylaluminoxane (MAO) catalysts was investigated. The results obtained in this study demonstrate that the molecular weight control of the polymers is possible in the polymerization of VC with the Cp*Ti(OPh)3/MAO catalyst.

    8. Synthesis and properties of hyperbranched polyurethanes, hyperbranched polyurethane copolymers with and without ether and ester groups using blocked isocyanate monomers (pages 3877–3893)

      Mahalingam Vanjinathan, A. Shanavas, A. Raghavan and A. Sultan Nasar

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22138

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      Hyperbranched poly(ether–urethane)s and poly(ester–urethane)s were synthesized using AB2-type blocked isocyanate monomers. Hyperbranched polyurethane copolymers were also synthesized using functionally similar AB-type blocked isocyanate monomers. The molecular weights (Mw) of the polymers were found to vary from 1.5 × 104 to 1.2 × 106. Hyperbranched poly(ether–urethane)s and poly(ester–urethane)s were found to be thermally stable up to 245 and 300 °C, respectively. It was found that Tgs of polyurethane were significantly reduced when introducing the ether group. End-capping of polymers were carried out using polyethylene glycol monomethyl ether (Mn = 550) and decanol.

    9. Synthesis of AB-type block copolymers containing benzoxazole and anthracene groups by ATRP and fluorescent property (pages 3894–3901)

      Jian-Mei Lu, Qing-Feng Xu, Xin Yuan, Xue-Wei Xia and Li-Hua Wang

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22139

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      Monomer, methacrylic acid 4-(2-benzoxazol)-benzyl ester (MABE) was synthesized and polymerized via atom transfer radical polymerization and it was utilized as a microinitiator to polymerize 4-(2-(9-anthryl))-vinyl-styrene (AVS) forming diblock copolymers poly(MABE-b-AVS). With the excitation at λex = 330 nm, the emission spectrum of poly(MABE) solution shows a single band at 375 nm, while that of poly(MABE-b-AVS) solution shows a broad band from 330 to 600 nm when mole ratio of the monomer AVS was 0.31. However, the emission spectrum of poly(MABE-b-AVS) film shows single band at 525 nm corresponding to the anthracene group which indicates complete energy transfer from the benzoxazole group to the anthracene group.

    10. Polyurethane/polyaniline and polyurethane-poly(methyl methacrylate)/polyaniline conductive core-shell particles: Preparation, morphology, and conductivity (pages 3902–3911)

      Chien-Yu Li, Wen-Yen Chiu and Trong-Ming Don

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22140

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      Polyurethane/polyaniline (PU/PANI) and polyurethane-poly(methyl methacrylate)/polyaniline (PU-PMMA/PANI) conductive core-shell particles were synthesized by a two-stage polymerization process. Hydrogen chloride (HCl) and dodecyl benzenesulfonic acid (DBSA) were used as the dopant agents. UV–visible spectra revealed that the polaron band was blue-shifted due to the more coiled conformation of PANI chains by increasing the concentration of DBSA. Besides, with a high concentration of DBSA, both spherical- and rod-shape PANI particles were observed by transmission electron microscope (TEM).

    11. Synthesis and morphology of Fe3O4/polystyrene/poly(isopropylacrylamide-co-methyl acrylate acid) magnetic composite latex – 2,2′-azobis (2-methylpropionamidine) dihydrochloride as initiator (pages 3912–3921)

      Chia-Fen Lee, Yu-Hui Chou and Wen-Yen Chiu

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22142

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      Fe3O4/polystyrene/poly(N-isopropylacryl amide-co-methylacrylate acid) magnetic composite latex was synthesized by two stage emulsion polymerization. Fe3O4 particles were surface treated by either PAA oligomer or lauric acid to form the stable ferrofluid. The first stage for the synthesis of magnetic composite latex was to synthesize PS in the presence of ferrofluid to form the Fe3O4/PS particles. The second stage of polymerization was carried out by soapless emulsion polymerization with NIPAAM and MAA as monomers and Fe3O4/PS latex as seeds. The mechanisms of the first stage reaction and second stage reaction were investigated. The effects of PAA and lauric acid on the reaction kinetics, morphology and particle size distribution were studied.

    12. Studies on curing kinetics of a novel combined liquid crystalline epoxy containing tetramethylbiphenyl and aromatic ester-type mesogenic group with diaminodiphenylsulfone (pages 3922–3928)

      Zhi-Qi Cai, Jianzhong Sun, Daodeng Wang and Qiyun Zhou

      Article first published online: 18 JUL 2007 | DOI: 10.1002/pola.22143

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      The curing kinetics of a novel liquid crystalline epoxy resin with combining biphenyl and aromatic ester-type mesogenic unit, diglycidyl ether of 4,4′-bis(4-hydroxybenzoyloxy)-3,3′,5,5′-tetramethyl biphenyl (DGE-BHBTMBP), and the curing agent diaminodiphenylsulfone (DDS) was studied using the advanced isoconvensional method (AICM). Figure 4 depicts dependence of the effective activation energy on the extent of conversion calculated by AICM (points) and the dependence of the extent of conversion on temperature (line) at the heating rate of 10 °C/min for DGE-BHBTMBP/DDS curing system.

    13. Electrosyntheses of high-quality polyphenanthrene in the electrolyte of boron trifluoride diethyl etherate containing trifluoroacetic acid (pages 3929–3940)

      Guangming Nie, Xuejun Han, Shusheng Zhang and Qingli Wei

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22144

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      A novel inherently conducting polymer, high-quality polyphenanthrene (PPh) films with a conductivity of 0.68 S cm−1, was synthesized electrochemically by direct anodic oxidation of phenanthrene (Ph) in boron trifluoride diethyl etherate (BFEE) containing 35% trifluoroacetic acid (TFA) (by volume) directly. However, similar oxidation using acetonitrile never produce such a polymeric material. As-formed PPh films showed good redox activity and high electrochemical and thermal stability. Fluorescence spectrum of dedoped PPh was examined with CH2Cl2 as the solvent, as shown in this Figure. The fluorescence spectra indicated that the polymer was a good blue light emitter and this soluble PPh may find applications in various fields, such as organic laser with blue emitting polymers and a very promising candidate for use as an electron transporting material in LEDs with magnesium cathodes.

    14. Exploring pathways to reduce the distribution of active sites in the Ziegler–Natta polymerization of propylene (pages 3941–3948)

      David Ribour, Valérie Bollack-Benoit, Vincent Monteil and Roger Spitz

      Article first published online: 10 JUL 2007 | DOI: 10.1002/pola.22146

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      Chemical modifications of Ziegler–Natta precatalysts with bulky mono- or multidentate ligands were performed to attempt to reduce the distribution of active sites in the polymerization of propylene. With multidentate ligands, in addition to a poisoning of active sites observed also with monodentate ligands, an extraction of titanium from the catalyst surface occurred and a slight modification of the distribute properties of polypropylenes was observed (decrease of isotacticity and narrowing of the molecular weight distribution). This study also underlined that the distributed properties of polymers are due to the chemical diversity of the active sites and not to mass transfer limitations.

    15. Synthesis and characterization of well-defined [polystyrene-b-poly(2-vinylpyridine)]n star-block copolymers with poly(2-vinylpyridine) corona blocks (pages 3949–3955)

      Haining Ji, Georgios Sakellariou, Rigoberto C. Advincula, Grant D. Smith, S. Michael Kilbey II, Mark D. Dadmun and Jimmy W. Mays

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22148

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      A two-step living anionic polymerization method was used to synthesize homologous series of [polystyrene-b-poly(2-vinylpyridine)]n star-block copolymers with the poly(2-vinylpyridine) blocks at the periphery. Firstly, oligo(styryl)lithium grafted poly(divinylbenzene) cores were used as multifunctional initiators to initiate living anionic polymerization of styrene in benzene at room temperature. Secondly, vinylpyridine was polymerized at the periphery of these living (polystyrene)n stars in tetrahydrofuran at −78 °C. These materials will serve as model compounds for use in creation and characterization of well-defined multiply bound polymer chains.

    16. Preparation of carboxyl-end-group polyacrylamide with low polydispersity by ATRP initiated with chloroacetic acid (pages 3956–3965)

      Jianguo Jiang, Xiaoyan Lu and Yun Lu

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22149

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      ATRP of acrylamide was carried out with chloroacetic acid as initiator and CuCl/N,N,N′,N′-tetramethylethylenediamine (TMEDA) as catalyst either in water at 80 °C or in glycerol–water (1:1 v/v) medium at 130 °C, affording carboxyl-end-group polyacrylamide with lower polydispersity ranging from 1.03 to 1.44. The chloroacetic acid not only served as a functional initiator for the ATRP of acrylamide but also provided the acidic polymerization condition, effectively protecting the ATRP of acrylamide from the unexpected complexation and cyclization side-reactions.

    17. Novel synthesis of biodegradable star poly(ethylene glycol)-block-poly(lactide) copolymers (pages 3966–3974)

      Yahia Lemmouchi, Michael C. Perry, Allan J. Amass, Khirud Chakraborty and Etienne Schacht

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22150

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      The synthesis of star-poly(lactide)-block-poly(ethylene glycol) copolymers has been carried out using a novel catalyst, potassium hexamethyldisilazide, and poly(ethylene glycol) as initiator to yield polymers of controlled molecular weight and narrow polydispersity. The polymerization went to complete conversion at room temperature. A wide range of block copolymers with different compositions and architectures have been prepared. The formation of block copolymers was confirmed by GPC, NMR, and DSC analyses.

    18. Novel synthesis of biodegradable amphiphilic linear and star block copolymers based on poly(ε-caprolactone) and poly(ethylene glycol) (pages 3975–3985)

      Yahia Lemmouchi, Michael C. Perry, Allan J. Amass, Khirud Chakraborty and Etienne Schacht

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22151

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      The synthesis of linear and star block copolymers based on poly(ε-caprolactone) and poly(ethylene glycol) has been carried out using a novel catalyst, potassium hexamethyldisilazide, and poly(ethylene glycol) as initiator to yield polymers of controlled molecular weight and of narrow polydispersity. The polymerization went to complete conversion at room temperature. A wide range of block coploymers with different compositions and architectures have been prepared. The formation of block copllymers was confirmed by GPC, NMR and DSC analyses.

    19. Ring-opening metathesis polymerization of functionalized cyclooctene by a ruthenium-based catalyst in ionic liquid (pages 3986–3993)

      Huijing Han, Fengxiang Chen, Jiahui Yu, Jingya Dang, Zhuo Ma, Yiqun Zhang and Meiran Xie

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22152

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      Novel monomer of 5-substituted cyclooctene with the pendant of imidazolium salt (7) was synthesized, and ROMP of the functionalized cyclooctenes (4 and 7) was carried out in CH2Cl2 and ionic liquid by catalyst 2. The polymerization performances of 4 and 7 were much different in CH2Cl2 and ionic liquid. The charged polymers (poly-7) were hydrolyzed to give uncharged polymers (poly-4*), which facilitated the GPC measurement for the molecular weight of polymers.

    20. Codendronized polymers pendent with alternating dendritic wedges (pages 3994–4001)

      Yanhong Zhang, Zizhen Xu, Xiaokai Li and Yongming Chen

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22153

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      A new dendronized polymer, codendronized polymers bearing two different dendritic wedges in an alternating structure was presented. Since the pendent dendrons were different and each of them was well-defined, such codendronized polymer can be a multi-compartment worm-like molecule. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    21. Novel use of mesoporous aluminas as supports for Cp2ZrCl2 and Cp*ZrMe3: Ethylene polymerization and formation of polyethylene nanofibers (pages 4002–4012)

      Jani P. J. Turunen, Tapani Venäläinen, Sari Suvanto and Tuula T. Pakkanen

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22154

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      Mesoporous aluminas were prepared by anodization of an aluminum film and by the templating method, and for the first time used as supports for metallocene catalysts in ethylene polymerization. Cp2ZrCl2 and (η5-Me5Cp)ZrCl3, which were used as the supported metallocenes, polymerized ethylene with activities comparable to similar silica-supported metallocenes. Partially fibrous polyethylene was produced with all of the heterogeneous catalysts, but also with the unsupported Cp2ZrCl2 and (η5-Me5Cp)ZrMe3.

    22. Synthesis of graft copolymers with “V-shaped” and “Y-shaped” side chains via controlled radical and anionic polymerizations (pages 4013–4025)

      Fengping Yu, Junpo He, Xiaojun Wang, Guangzheng Gao and Yuliang Yang

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22155

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      The graft (co)polymers with “V-shaped” and “Y-shaped” side chains are synthesized via anionic and controlled radical polymerizations. The resulting polymer products exhibit lower viscosities and radii of gyration than the linear polystyrene because of their nonlinear architectures in dilute solution.

    23. Aromatic polyamides with pendant urea moieties (pages 4026–4036)

      Noelia San-José, Ana Gómez-Valdemoro, Félix Clemente García, Felipe Serna and José Miguel García

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22156

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      This work describes six novel aromatic polyisophthalamides with bulky pendant urea groups. The polyamides are amorphous and soluble in polar aprotic solvents. They demonstrate a film-forming capability with outstanding mechanical properties, and exhibit moderate thermal resistance in a nitrogen and in oxygen atmospheres. The urea group imparts hydrophilicity to the polymers, and facilitates the future preparation of specialty polymers through the easy chemical modification of this group.

    24. Novel synthesis of rod-coil block copolymers by combination of coordination polymerization and ATRP (pages 4037–4042)

      Koji Ishizu, Naomasa Hatoyama and Satoshi Uchida

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22157

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      Combination of coordination polymerization and atom transfer radical polymerization (ATRP) was applied to a novel synthesis of rod-coil block copolymers. Coordination polymerization of n-butyl isocyanate (BIC) initiated the complex catalyst CpTiCl3(α-bromo, ω-hydroxy bifunctional initiator), where Cp = cyclopentadienyl, provide the macroinitiator PBIC-Br having a terminal bromine atom. Well-defined rod-coil block copolymers PBIC-block-polystyrene (PS) and PBIC-block-poly(methyl methacrylate) (PMMA) were prepared by ATRP approach initiated by PBIC-Br.

    25. 2,4,6-trichlorophenyl acrylate emulsion-templated porous polymers (PolyHIPEs). Morphology and reactivity studies (pages 4043–4053)

      Nermina Leber, Jonathan D. B. Fay, Neil R. Cameron and Peter Krajnc

      Article first published online: 11 JUL 2007 | DOI: 10.1002/pola.22158

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      The polymerization of the continuous phases of high internal phase emulsions yielded highly porous monolithic polymers with open cellular architecture. 2,4,6-Trichlorophenyl acrylate was included in the organic phase as a reactive group to enable functionalizations of polymers. Tris(2-aminoethyl)amine was used to immobilize amino groups and hydrolysis of ester groups to gain acid groups. The addition of porogenic solvents (toluene, chlorobenzene, chloroform, and dichloroethane) revealed the influence on surface area and void sizes.

    26. Effects of hydrogen in ethylene polymerization and oligomerization with magnesium chloride-supported bis(imino)pyridyl iron catalysts (pages 4054–4061)

      Rubin Huang, Cor E. Koning and John C. Chadwick

      Article first published online: 11 JUL 2007 | DOI: 10.1002/pola.22159

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      Investigation of the effects of hydrogen on ethylene polymerization using magnesium chloride-supported bis(imino)pyridyl iron catalysts revealed that the presence of hydrogen leads to deactivation of active species producing low molecular weight polymer. The decreased formation of vinyl-terminated oligomers able to retard polymer chain growth by 2,1-insertion into the growing chain is likely to be an important factor in the overall activating effect of hydrogen in ethylene polymerization with immobilized iron catalysts.

    27. The influence of N-vinyl pyrrolidone on polymerization kinetics and thermo-mechanical properties of crosslinked acrylate polymers (pages 4062–4073)

      Timothy J. White, William B. Liechty and C. Allan Guymon

      Article first published online: 11 JUL 2007 | DOI: 10.1002/pola.22173

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      A common reactive diluent to photopolymerizable formulations is N-vinyl pyrrolidone (NVP) which is known to reduce the inhibition of free radical photopolymerization by atmospheric oxygen. In this work, the copolymerization behavior of NVP is examined in mixtures with acrylate monomers with two to five functional groups. The copolymerization behavior of NVP/acrylate systems is dependent on monomer functionality. The diffusional constraints in high functionality acrylate polymerization differentiate the impact of NVP on polymerization rate, double bond conversion, and reaction diffusion controlled termination. The effects of NVP on polymerization behavior are also correlated to characterization of thermo-mechanical properties of NVP/acrylate copolymers.

    28. Amphiphilic conetworks. III. Poly(2,3-dihydroxypropyl methacrylate)–polyisobutylene and poly(ethylene glycol) methacrylate–polyisobutylene based hydrogels prepared by two-step polymer procedure (pages 4074–4081)

      Miroslav Janata, Luděk Toman, Jiří Spěváček, Jiří Brus, Antonín Sikora, Petra Látalová, Petr Vlček, Jiří Michálek and Barbora Dvořánková

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22181

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      Amphiphilic conetworks consisting of poly(2,3-dihydroxypropyl methacrylate) and poly(ethylene glycol) methacrylate and polyisobutylene (PIB) chains were prepared from a cationic copolymer of isobutylene (IB) and 3-isopropenyl-α,α-dimethylbenzyl isocyanate (IDI). The isocyanate groups of the IB-IDI random copolymer were transformed in situ to methacrylate (MA) groups by the reaction with 2-hydroxyethyl methacrylate. The resulting methacrylate multifunctionalized polyisobutylene, PIB(MA)n, was then copolymerized radically with 2,3-dihydroxypropyl methacrylate or poly(ethylene glycol) methacrylate giving rise to amphiphilic conetworks.

    29. A novel rate-accelerating additive for atom transfer radical polymerization of styrene (pages 4082–4090)

      Zhuang Jiaming, Lin rui, Huang Jianying, Chu Jiayan, Lin Xurong, Luo Yutai and Zou Yousi

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22217

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      Compared with typical ATRP of styrene, the polymerization has been enhanced in the presence of MN by a factor of 1.80, 2.40 2.67 respectively, at 65 °C, 75 °C and 85 °C. A perfect controllability has been preserved in the presence of MN especially over 85 °C. The possible explanation to the rate enhancement may attribute to the weaker coordination between copper and ligand via the interaction between MN and ligand facilitating the atom transfer process. The disproportionation of copper(I) can also enhance the polymerization.

    30. Thermogelling hydrogels of poly(ε-caprolactone-co-D,L-lactide)–poly(ethylene glycol)–poly(ε-caprolactone-co-D,L-lactide) and poly(ε-caprolactone-co-L-lactide)–poly(ethylene glycol)–poly(ε-caprolactone-co-L-lactide) aqueous solutions (pages 4091–4099)

      Zhiqiang Jiang, Xianmo Deng and Jianyuan Hao

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22222

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      Thermogelling poly(ε-caprolactone-co-D,L-lactide)–poly(ethylene glycol)–poly(ε-caprolactone-co-D,L-lactide) triblock copolymers were synthesized through the ring-opening polymerization of ε-caprolactone and D,L-lactide with poly(ethylene glycol). Aqueous solutions of poly(ε-caprolactone-co-D,L-lactide)–poly(ethylene glycol)–poly(ε-caprolactone-co-D,L-lactide) (1630–1540–1630) underwent a sol-to-gel transition from room temperature to body temperature. The critical gelation temperature could be controlled by the structure parameters, such as the block length of the polymers and the microstructures.

    31. Isoprene polymerization via reversible addition fragmentation chain transfer polymerization (pages 4100–4108)

      David S. Germack and Karen L. Wooley

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22226

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      The kinetics for the polymerization of isoprene via RAFT are determined. Moreover, the preparation of isoprene block copolymers is described.

    32. Linear polyurethanes derived from alditols and diisocyanates (pages 4109–4117)

      Ma Violante de Paz, Romina Marín, Francisca Zamora, Khalid Hakkou, Abdelilah Alla, Juan A. Galbis and Sebastián Muñoz-Guerra

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22127

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      Linear polyurethanes containing attached methoxy groups were prepared by polycondensation of sugar-derived treitols or pentitols with either aliphatic or aromatic diisocianates. All these novel polyurethanes are amorphous regardless of what is the configuration of the sugar moiety. They display higher Tg than their nonsubstituted homologous but the thermal properties are scarcely influenced by the chemical constitution of the alditol. On the contrary, their hydrodegradability appeared to be largely determined by the length of the polymethoxy alkylene segment present in the polymer chain.

    33. Novel michael addition networks containing urethane hydrogen bonding (pages 4118–4128)

      Sharlene R. Williams, Brian D. Mather, Kevin M. Miller and Timothy E. Long

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22236

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      The Michael addition reaction was utilized to prepare covalently crosslinked networks based on poly(propylene glycol) bis(acetoacetate) with either neopentyl glycol diacrylate or hydroxyethyl acrylate derivatized bis(4-isocyanatocyclohexyl)methane (HMDI). These networks were prepared in the presence of catalytic quantities of diazabicyclo[5.4.0]undec-7-ene (DBU) in the absence of solvent at 23 °C without the formation of byproducts. Mechanical and thermal analyses of the networks were performed utilizing DMA, tensile testing, and TGA. Higher tensile strengths and elongation to break compared with nonhydrogen-bonding analogs resulted when hydrogen-bonding urethane linkages were introduced in the diacrylate segment.

    34. Polyelectrolyte complexation between poly(methacrylic acid, sodium salt) and poly(diallyldimethylammonium chloride) or poly[2-(methacryloyloxyethyl) trimethylammonium chloride] (pages 4129–4143)

      Nicholas A. D. Burke, M. A. Jafar Mazumder, Mark Hanna and Harald D. H. Stöver

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22247

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      Complexation of PMAANa with the quaternary ammonium polycations PDADMAC or PMOETAC lead to either gelled, liquid or soluble polyelectrolyte complexes, depending on charge ratio, polymer loading, molecular weight, and ionic strength. The complex phases swelled with increasing polymer loading, and merged with the supernatant phase at a critical loading. The liquid complex phases near this critical loading phase separate upon heating. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

  3. Rapid Communications

    1. Top of page
    2. Highlights
    3. Articles
    4. Rapid Communications
    5. Notes
    1. You have free access to this content
      RAFT Copolymerization as a means to enhance the electro-optical performance of polymer dispersed liquid crystal films (pages 4144–4149)

      Jie He, Bin Yan, Shoulian Wang, Binyu Yu, Xiaoan Wang and Yinghan Wang

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22121

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      Polymer as an important component of polymer-dispersed liquid crystal film has great influence on the electro-optical properties. Polystyrene was prepared as a macro-RAFT agent in this study. Poly(methyl acrylate)-co-polystyrene was prepared in situ and used as polymer matrix in photopolymerization induced phase separation. A lager reduction in the threshold voltage and saturation voltage was observed. The electro-optical properties of PDLC films were enhanced greatly.

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      Versatile synthetic approach to reversible crosslinked polystyrene networks via RAFT polymerization (pages 4150–4153)

      Yong-Keng Goh, Andrew K. Whittaker and Michael J. Monteiro

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22162

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      A versatile method to prepare crosslinked networks that can be reduced to the starting polymer—a recyclable material. Controlling the molecular weight of the trifunctional polymer is the key for controlling the polymer architecture. The use of low-molecular-weight three-arm stars favors linear multiblocks with the possibility of intracyclization after oxidation, whereas at higher molecular weight starting three-arm stars, linear multiblocks and crosslinking are favored.

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      Synthesis of poly[2]rotaxane by Sonogashira polycondensation (pages 4154–4160)

      Hisahiro Sasabe, Norihiro Inomoto, Nobuhiro Kihara, Yuichi Suzuki, Akiya Ogawa and Toshikazu Takata

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22204

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      Head-to-tail poly[2]rotaxane without intercomponent interaction.

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      Surface grafting of polyimide onto silicon surface: Preparation and characterization (pages 4161–4167)

      Ying-Ling Liu, Shih-Chun Chen and Chuan-Shun Liu

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22255

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      This work reports the attempt of incorporation of polyimide chains onto silicon surfaces from an amino-terminated silicon Si-GPE-NH2, which is obtained from glycidylphenylether (GPE)-functionalized silicon and nitration/reduction reactions of the attached GPE moieties. The presence of polyimide chains on silicon surfaces and the surface morphology change along with the modifications were characterized with XPS and AFM analysis, respectively.

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      Chain transfer to ionic liquid in an anionic polymerization of methyl methacrylate (pages 4168–4172)

      Tadeusz Biedroń and Przemyslaw Kubisa

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22256

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      When methyl methacrylate is polymerized with alkyllithium as initiator in imidazolium ionic liquids, low molecular weight polymers are formed in high yield. The head-groups are, however, not those alkyl groups that are present in alkyllithium, but predominantly those that are originally present at 1-position in imidazolium cation indicating extensive chain transfer to imidazolium ionic liquid.

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      Synthesis and aggregation properties of anionic star-shaped polymers with cholic acid cores and polyacrylate arms (pages 4173–4178)

      Guillaume Giguère and X. X. Zhu

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22257

      Thumbnail image of graphical abstract

      Cholic acid is modified chemically to serve as an ATRP initiator for the preparation of star-shaped polymers with four poly(t-butyl acrylate) arms. The length of the arms is identical and can be varied. The amphiphilic property of cholic acid is retained as evidenced by the aggregation of the star polymers after a partial cleavage of the t-butyl groups.

  4. Notes

    1. Top of page
    2. Highlights
    3. Articles
    4. Rapid Communications
    5. Notes
    1. You have free access to this content
      Synthesis of PS(PEO)3 star block copolymers from a heterotetrafunctional initiator (pages 4179–4183)

      O. Glaied, C. Delaite and P. Dumas

      Article first published online: 17 JUL 2007 | DOI: 10.1002/pola.22147

      Thumbnail image of graphical abstract

      Well-defined amphiphilic PS(PEO)3 star block copolymers have been obtained for the first time through the use of a new partially protected heterotetrafunctional initiator, by coupling ATRP of styrene and anionic Ring-Opening Polymerization (ROP) of EO. This two-step synthesis implies first the obtaining of a PS macroinitiator with three alcohols of same reactivity for the growth of three PEO blocks.

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