Journal of Polymer Science Part A: Polymer Chemistry

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

15 October 2008

Volume 46, Issue 20

Pages 6677–6982

  1. Highlights

    1. Top of page
    2. Highlights
    3. Articles
    4. Note
    1. You have free access to this content
      Synthesis of well-defined polymeric activated esters (pages 6677–6687)

      Patrick Theato

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22994

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      This Highlight Article summarizes recent studies on the controlled polymerization of activated ester monomers as well as the preparation of surfaces modified with activated esters. Techniques, such as ATRP, NMP, RAFT polymerization or ROMP, proved to be extremely versatile tools on polymerizing activated ester based monomers with unprecedented precision, thereby providing extremely useful materials for interdisciplinary sciences like nanotechnology or bioconjugation of polymers. Even though, the chemistry of activated esters is a rather old topic in polymer chemistry, it appears to gain a dramatic new momentum and further exciting results are very likely. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]

  2. Articles

    1. Top of page
    2. Highlights
    3. Articles
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    1. Linear and A2+B3-type hyperbranched polyesters comprising phenylbenzothiazole unit: Preparation, liquid crystalline, and optical properties (pages 6688–6702)

      Moriyuki Sato, Atsushi Nakashima, Yuzuru Sato and Isao Yamaguchi

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22976

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      Liquid crystalline (LC) hyperbranched (HB) polyesters comprising phenylbenzothiazole (PBT) unit in the interiors were successfully prepared by solution polycondensation under various feed mole ratios (A2/B3) via A2+B3 approach and their LC and optical properties were compared with the corresponding LC linear polyesters containing the PBT unit in the main chains. The structures of HB polymers varied depending on the feed mole ratios of A2 monomer to B3 monomer (A2/B3), and the HB polymers (A2/B3 = 3/1 and 2/1) having terminal OH or acetoxy group formed smectic A or C phase, whereas the linear polymer showed no LC phase. Solution UV-vis and photoluminescent spectra indicated that the linear and HB polymers have analogous optical properties and display maximum absorbances and blue-light emission on the basis of the PBT unit, but there was a large difference between their absorption properties in film.

    2. A2B2 type miktoarm star copolymers via alkyne homocoupling reaction (pages 6703–6711)

      Eda Gungor, Gurkan Hizal and Umit Tunca

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22977

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      The terminal alkyne homocoupling reaction (oxidative alkyne coupling) is presented here as a new route for the preparation of A2B2 type 4-miktoarm star copolymer. The block copolymer with terminal alkyne at the junction point prepared by NMP-ATRP and ROP-NMP sequential routes is coupled via diyne formation to give (PS)2-(PMMA)2 and (PCL)2-(PS)2 4-miktoarm star polymers, respectively using a combination of (PPh3)2PdCl2/PPh3/CuI in a solvent mixture of Et3N/CH3CN at room temperature for 72 h. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    3. Self-assembly of N-carboxyethylchitosan near the isoelectric point (pages 6712–6721)

      Rosica Mincheva, François Bougard, Dilyana Paneva, Magali Vachaudez, Nevena Manolova, Philippe Dubois and Iliya Rashkov

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22978

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      Self-assembly of N-carboxyethylchitosan occurs near its isoelectric point (pH 5.0–5.6). Spherically shaped (average diameter: 30–380 nm) or rod/worm-like (average diameter: 20 nm) nanosized assemblies are formed depending on the polymer molar mass, pH value, and polymer concentration. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    4. Synthesis of a [60] fullerene—Functionalized isotactic polypropylene derivative (pages 6722–6733)

      Gerardo Martínez, Marián A. Gómez, Carlos Marco, Gary Ellis, Rafael Gómez and José L. Segura

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22979

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      Addition of the C60 moiety, a powerful electron acceptor, to isotactic polypropylene (i-PP) in the presence of dicumyl peroxide (DCP) considerably modifies the chemical and physical properties of this polymer. The reaction mechanism proceeds via the formation of i-PP radicals by reaction with DCP radicals, followed by addition of the polymeric carbon radicals to the C60. The fullerenated i-PP samples obtained show high crystallinity, and the global process of thermal degradation is enhanced by the C60-chemical modification. The resulting functionalized polymers also show good electron acceptor properties as evidenced by electrochemical studies, where cyclic voltamograms of the C60 functionalized polymers display reversible reduction waves which can be assigned to electron reduction processes of the C60 moiety.

    5. Silicon-containing azo polymers with paired mesogens and their applications to optical memory media (pages 6734–6745)

      Min-Jeong Lee, Han-Na Ji and Yang-Kyoo Han

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22980

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      Novel silicon containing azo polymers with two symmetrical mesogens were synthesized and evaluated for use as reversible optical data storage media. The high photoinduced orientation of paired azo mesogens allows the polymers to develop not only better resolution (up to 0.6 μm, left) in the recorded data but also high sensitivity. The copolymers also exhibited strong potential that could be used as a holographic memory material (volume hologram) using two-wave mixing technique. High-quality holographic grating patterns were inscribed even in the copolymer film with azo molar content of only 7.0% using a low-power energy laser. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    6. Living cationic polymerization of vinyl ethers in the presence of a strong base: Poisonous or helpful? (pages 6746–6753)

      Motomasa Yonezumi, Nanako Takano, Shokyoku Kanaoka and Sadahito Aoshima

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22982

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      Living cationic polymerization of an alkyl vinyl ether was achieved in toluene at 0 °C using a certain Lewis acid (SnCl4, TiCl4, and ZnCl2) combined with a small amount of a strong base (N,N-dimethylacetamide) (Mw/Mn ≤ 1.1). This polymerization system differed from the weak base counterparts in terms of the optimum additive amount, the Lewis acid preference, and the polymerization rate. The systems with a strong base required much less quantity of bases than weak base systems for living polymerization. In addition, amine derivatives as stronger bases allow living polymerization even in the presence of a catalytic quantity.

    7. Preparation of star block copolymers with polystyrene-block-poly(ethylene oxide) as side chains on hyperbranched polyglycerol core by combination of ATRP with atom transfer nitroxide radical coupling reaction (pages 6754–6761)

      Chao Liu, Mugang Pan, Yi Zhang and Junlian Huang

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22983

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      The star block copolymers with polystyrene-block-poly(ethylene oxide) (PS-b-PEO) as side chains and hyperbranched polyglycerol (HPG) as core were synthesized via the combination of ATRP with “atom transfer nitroxide radical coupling” (“ATNRC”) reaction. The final products and intermediates were characterized in details. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    8. Synthesis and characterization of fluorene-based copolymers containing benzothiadiazole derivative for light-emitting diodes applications (pages 6762–6769)

      Kyung-Jin Yoon, Jin Su Park, Seung-Joon Lee, Myungkwan Song, In Ae Shin, Jae Wook Lee, Yeong-Soon Gal and Sung-Ho Jin

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22984

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      Five new thermally robust electroluminescent fluorene-based conjugated copolymers, including poly[2,7-(9,9-dioctylfluorene)-co-4,7-{5,6-bis(3,7-dimethyloctyloxymethyl)-2,1,3-(benzothiadiazole)}] (PFO-P2C10BT) were synthesized and used to fabricate the efficient polymer light-emitting diodes (PLEDs). We fabricated PLEDs in ITO/PEDOT/light-emitting polymer/cathode configurations using either double-layer LiF/Al or triple-layer Alq3/LiF/Al cathode structures. The maximum brightness and luminance efficiency of these PLEDs were found to be up to 5347 cd/m2 and 1.51 cd/A at 10 V, respectively.

    9. One-pot synthesis of heterograft copolymers via “graft onto” by atom transfer nitroxide radical coupling chemistry (pages 6770–6779)

      Qiang Fu, Chao Liu, Wencheng Lin and Junlian Huang

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22985

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      Well-defined poly(GTEMPO-co-EO)-g-PS/PtBA heterograft copolymers were prepared in one-pot by atom transfer nitroxide radical coupling (ATNRC) reaction via “graft onto”. The density of GTEMPOs on precursor copolymer poly(GTEMPO-co-EO), the structure of macroradicals, molecular weights of side chains PS-Br and PtBA-Br can exert great effect on the coupling efficiency. The PS radicals are more reactive than that of PtBA in the coupling reaction. This approach can afford a useful strategy for synthesis of heterograft copolymers with various compositions and well-defined structures. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    10. Synthesis and characterization of nanomagnetite thermosets based on benzoxazines (pages 6780–6788)

      Baris Kiskan, A. Levent Demirel, Orhan Kamer and Yusuf Yagci

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.23023

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      Nanomagnetite thermosets were obtained by thermally activated ring opening copolymerization of benzoxazine groups coated on the surface of the nanomagnetite with bare benzoxazine. For this purpose, carboxylic acid containing 1,3-benzoxazine was synthesized and covalently bonded on magnetite nanoparticles by post-coating method. Magnetic and thermal properties of the cured samples were investigated. It was shown that the precursor nanomagnetite banzoxazine and cured samples exhibited typical ferromagnetic character with low coercivities between 1.5 and 2.5 Oe. The cured samples showed high thermal stability.

    11. 2D- and 3D-microstructured biodegradable polyester resins (pages 6789–6800)

      Cristian Vaida, Petra Mela, Helmut Keul and Martin Möller

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22987

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      Biodegradable polyester resins were prepared via photo crosslinking of functional polyesters obtained by copolymerization of ε-caprolactone and the functional cyclic esters γ-acryloyloxy-ε-caprolactone and γ-methacryloyloxy-ε-caprolactone. 3D-micropatterning of the copolymers was performed via UV-crosslinking of polymer films on a suitable substrate and by UV replica molding on both rigid and elastic masters. Via replica molding objects with a variety of structures such as pillars, holes, ridges, and grooves were prepared, showing the processability of these resins and providing interesting materials for biomedical applications.

    12. Synthesis and characterization of polycholesteryl methacrylate–polyhydroxyethyl methyacrylate block copolymers (pages 6801–6809)

      Yuxiang Zhou and Rajeswari M. Kasi

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22988

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      New synthetic methods have been used to prepare novel diblock copolymers, poly(cholesteryl methacrylate-b-2-hydroxyethyl methacrylate) (PCMA-b-PHEMA). These amphiphilic diblock copolymers comprise rod-blocks with cholesterol side-chain liquid crystalline mesogens and coil block capable of hydrogen bonding. These diblock copolymers have potential biomedical applications in tissue engineering and cellular scaffolding. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley. com.]

    13. Alternating copolymerization of cyclohexene oxide and carbon dioxide catalyzed by noncyclopentadienyl rare-earth metal bis(alkyl) complexes (pages 6810–6818)

      Zhichao Zhang, Dongmei Cui and Xinli Liu

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22989

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      A series of rare-earth metal bis(alkyl) complexes supported by β-diimine ligands have been synthesized and structurally characterized. All the complexes were applied as single-component catalysts to the copolymerization of cyclohexene oxide and carbon dioxide. Methoxy-modified β-diiminato yttrium complex (2-CH3O(C6H4)N[DOUBLE BOND]C(CH3)CH[DOUBLE BOND]C(CH3)N(2-CH3O (C6H4))Y(CH2SiMe3)2 (1a) effectively converted cyclohexene oxide and CO2 to polycarbonate with more than 99% carbonate linkages and exhibited the highest catalytic activity of 47.4 h–1 in rare-earth metal catalyst systems. The factors that influenced the copolymerization were presented as well.

    14. Evolution of iron catalysts for effective living radical polymerization: P–N chelate ligand for enhancement of catalytic performances (pages 6819–6827)

      Chihiro Uchiike, Makoto Ouchi, Tsuyoshi Ando, Masami Kamigaito and Mitsuo Sawamoto

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22990

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      To increase activity of iron catalyst for living radical polymerization, we examined the ligand for FeBr2 focusing on “chelate.” In-situ coordination, just pre-mixing of these, for methyl methacrylate (MMA)-polymerization indicated that P–N hetero chelate-ligands (P: phosphine, N: nitrogen) was more effective than homo derivatives (i.e., P–P and N–N) in terms of activity and controllability of produced polymers. The isolated iron complex with the P–N chelate ligand [(R)-N,N-dimethyl-1-(2-(diphenylphosphino)phenyl)-ethanamine] induced fast polymerization (conv. ∼90% in 9 h) and gave narrow molecular weight distribution (Mw/Mn < 1.20). The catalyst was almost quantitatively removed only by water washing. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    15. Hydrogen-transfer reaction in nitroxide mediated polymerization of methyl methacrylate: 2,2-Diphenyl-3-phenylimino-2,3-dihydroindol-1-yloxyl nitroxide (DPAIO) vs. TEMPO (pages 6828–6842)

      Maria Edeleva, Sylvain R. A. Marque, Denis Bertin, Didier Gigmes, Yohann Guillaneuf, Sergey V. Morozov and Elena G. Bagryanskaya

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22991

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      In a recent paper it was shown that the NMP of methyl methacrylate was possible up to 80% conversion when nitroxide 2 was used as control agent. The decomposition of alkoxyamines 4-nitrophenyl 2-(2,2,6,6-tetramethylpiperidine-1-yloxy)-2-methylpropionate (1a) and 4-nitrophenyl 2-(2,2-diphenyl-3-phenylimino-2,3-dihydroindol-1-yloxy)-2-methylpropanoate (2a) has been studied by 1H NMR in the presence and in the absence of scavenger (thiophenol PhSH). At temperature lower than the one used for polymerization, fast and quantitative H-transfer reaction was observed for 1a whereas no H-transfer reaction was observed for 2a. The scavenging technique proved for the fist time that the H-transfer was an intermolecular process for 1a. However, the slow side-reaction of N[BOND]OC bond homolysis, which did not impede the control of the polymerization but may exert a detrimental effect on the livingness, was observed and quantified for 2a.

    16. A new enone-containing triglyceride derivative as precursor of thermosets from renewable resources (pages 6843–6850)

      L. Montero de Espinosa, J. C. Ronda, M. Galià and V. Cádiz

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22992

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      A novel triglyceride containing α,β-unsaturated ketone was prepared through photoperoxidation from high oleic sunflower oil by two steps one pot environmentally friendly procedure. This new enone-containing triglyceride was crosslinked with diaminodiphenylmethane (DDM) via aza-Michael addition as an alternative to epoxidized triglycerides. The thermal properties of thermosets from enone- and epoxy-containing triglycerides with DDM have been compared.

    17. Ring-opening metathesis polymerization of a modified linseed oil with varying levels of crosslinking (pages 6851–6860)

      T. C. Mauldin, K. Haman, X. Sheng, P. Henna, R. C. Larock and M. R. Kessler

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22995

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      A commercial, norbornyl-functionalized linseed oil was polymerized with various levels of crosslinking, facilitated with a bicyclic norbornene-based crosslinking agent (at loadings ranging from 0 to 50 wt %), by ring-opening metathesis polymerization (ROMP). The as-received linseed oil was found to consist of functionalized oil along with several low-molecular weight oligomers of cyclopentadiene, formed via a thermal cycloaddition. Samples varying from 0–50% crosslinker were studied by dynamic mechanical analysis, thermogravimetry, swelling tests, and Soxhlet extraction, and the delicate structure-property relationship between comonomers and thermoset polymer as it relates to microphase separation, crosslink density, mechanical properties and thermal stability is discussed in detail.

    18. Resistive switching polymer materials based on poly(aryl ether)s containing triphenylamine and 1,2,4-triazole moieties (pages 6861–6871)

      Kun-Li Wang, Tseung-Yuen Tseng, Hung-Lung Tsai and Sheng-Chieh Wu

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22996

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      A series of poly(aryl ether)s derived from a bipolar monomer containing triphenylamine and 1,2,4-triazole were prepared and used to test the behavior of resistive switching memory devices. The poly(aryl ether)s showed high thermal stability (Td10> 500 °C) and glass transition temperatures (Tg) higher than 187 °C as well as excellent solubility in organic solvents. The thin films of the poly(aryl ether)s indicated bistable resistive switching behavior, whereas the switching on and switching off bias voltages of the polymers were affected by the bisphenol moiety. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    19. Organic solvent dispersion of poly(3,4-ethylenedioxythiophene) with the use of polymeric ionic liquid (pages 6872–6879)

      Tae Young Kim, Tae Hee Lee, Jong Eun Kim, Rajeswari M. Kasi, Chong S. P. Sung and Kwang S. Suh

      Article first published online: 15 SEP 2008 | DOI: 10.1002/pola.22997

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      Organic solvent dispersion of poly(3,4-ethylenedioxythiophene) (PEDOT) was prepared with the use of polymeric ionic liquid (PIL) as a polymerization template and phase transfer medium. A detailed investigation was performed to understand the role of PIL in the course of polymerization and phase transfer reaction. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com].

    20. A comparative analysis of SET-LRP of MA in solvents mediating different degrees of disproportionation of Cu(I)Br (pages 6880–6895)

      Gerard Lligadas and Virgil Percec

      Article first published online: 12 SEP 2008 | DOI: 10.1002/pola.22998

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      The role of the disproportionating solvent in Cu(0)/Me6-TREN-catalyzed polymerization of MA initiated with methyl 2-bromopropionate at 25 °C is investigated. Cu(I)Br/Me6-TREN species are unstable and disproportionate into metallic Cu(0) and Cu(II)Br2/Me6-TREN in DMSO, whereas in toluene are stable and do not undergo disproportionation, at least at 25 °C. A combination of kinetic experiments and chain end analysis by 500-MHz 1H NMR spectroscopy is used to demonstrate that the selection of a solvent/ligand pair that mediates a fast disproportionation of Cu(I)Br is decisive to ensure a successful SET-LRP of MA at 25 °C. SET-LRP is accompanied by negligible irreversible termination and provides a polymer with perfect fidelity of its chain ends.

    21. Synthesis, characterization and cleavage of linear polymers attached to silica nanoparticles formed using thiol-acrylate conjugate addition reactions (pages 6896–6906)

      Vaibhav S. Khire, April M. Kloxin, Charles L. Couch, Kristi S. Anseth and Christopher N. Bowman

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.22999

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      Formation and cleavage of polymer films on surfaces using base-catalyzed thiol-acrylate conjugate addition reaction is investigated. A photocleavable acrylate is attached to silica nanoparticles and used as an anchoring group for the attachment of thiol-acrylate polymers, which are formed in the bulk via step growth mechanism. The modified particles are subsequently exposed to UV light to separate the films from the surface for characterization. Effect of monomer stoichiometry on grafted polymer properties such as molecular weight and surface coverage is investigated using this method. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    22. Synthesis, self-assembly, and thermosensitive properties of ethyl cellulose-g-P(PEGMA) amphiphilic copolymers (pages 6907–6915)

      Yanxiang Li, Ruigang Liu, Wenyong Liu, Hongliang Kang, Min Wu and Yong Huang

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.23000

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      Amphiphilic copolymers of ethyl cellulose graft poly(poly(ethylene glycol) methyl ether methacrylate) (EC-g-P(PEGMA)) were synthesized via atom transfer radical polymerization. The EC-g-P(PEGMA) copolymers can self-assemble into spherical micelles and show thermosensitive properties in water with a lower critical solution temperature around 65 °C. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    23. Oxygen scavengers and sensitizers for reduced oxygen inhibition in radical photopolymerization (pages 6916–6927)

      Michael Höfer, Norbert Moszner and Robert Liska

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.23001

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      In the present study, an approach to reduce oxygen inhibition in free-radical photopolymerization of (meth)acrylates by photosensitized generation of singlet oxygen and subsequent scavenging of this species by selective singlet oxygen scavengers was investigated. The potential of some 1,2-dione based photoinitiators to function as singlet oxygen sensitizers in visible light irradiation and the reactivity of singlet oxygen scavengers (furans, anthracenes) was tested in solution. The ability of systems containing singlet oxygen sensitizers/scavengers to reduce oxygen inhibition in practical applications was studied in thin film polymerization (ATR-FTIR).

    24. Kinetic study on the living/controlled cationic polymerization of p-methoxystyrene coinitiated by tris(pentafluorophenyl)borane (pages 6928–6939)

      Alexei V. Radchenko, Sergei V. Kostjuk, Irina V. Vasilenko, François Ganachaud, Fyodor N. Kaputsky and Yohann Guillaneuf

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.23002

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      A kinetic study on the living cationic polymerization of p-methoxystyrene using 1-(4-methoxyphenyl)-ethanol as initiator and B(C6F5)3 as a coinitiator in the presence of water ([H2O]/[B(C6F5)3] = 0-20) was performed. The propagation reaction order was found to be 1 and –2 with respect to Lewis acid coinitiator and water, respectively, while the apparent activation energy for the p-methoxystyrene polymerization was found high and positive (Ea,app = 62.4 kJ mol−1). Parameter estimation from experimental data with PREDICI yielded a rate constant of propagation kp = 4.9 × 104 L mol−1 s−1 and other constants confirming the main features of the polymerization scheme. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    25. Dichlorovanadium (IV) complexes with salen-type ligands for ethylene polymerization (pages 6940–6949)

      Marzena Białek and Krystyna Czaja

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.23003

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      Vanadium complexes with tetradentate [O,N,N,O] salen-type ligands were first time explored in ethylene polymerization. The efficiency of alkyl aluminum compounds as cocatalyst for the studied vanadium complexes decreases in the order: EtAlCl2 > Et2AlCl > Et3Al, and MAO seems to be the worst cocatalyst. The studied complexes, alike other vanadium-based systems, are susceptible to deactivation by temperature. The activity of a catalytic system is clearly influenced by structural changes within tetradentate ligands. All investigated vanadium complexes activated by common organoaluminum compounds give linear polyethylenes with high molecular weights and broad molecular weight distributions.

    26. Preparation of polypyrrole-graft-poly(N-isopropylacrylamide)/silver nanocomposites from pyrrolyl-capped macromonomer by AgNO3 and their stimuli responsibility of light emission (pages 6950–6960)

      Xiao-Li Sun, Wei-Dong He, Jian Li, Ning He, Shou-Chen Han and Li-Ying Li

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.23004

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      Pyrrolyl-capped poly(N-isopropylacrylamide) (Py-PNIPAM) was prepared by RAFT polymerization with benzyl 1-pyrrolyl-carbodithioate. Through oxidative coupling (co)polymerization of Py-PNIPAM with AgNO3 as oxidant, the composites of polypyrrole-graft-poly(N-isopropylacrylamide) and silver nanoparticles were obtained. Those nanocomposites are soluble in solvents and exhibit stimuli-sensitive fluorescence because of poly(N-isopropylacrylamide) graft chains and polypyrrole backbone.

    27. Imidazolium ionic liquids with short polyoxyethylene chains (pages 6961–6968)

      Tadeusz Biedroń and Przemysław Kubisa

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.23005

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      Polyoxyethylenes containing ionic liquid head group may easily be prepared by simple sequence of reactions involving reaction of imidazolium ionic liquids with paraformaldehyde to form imidazolium ionic liquids substituted at 2-position with [BOND]CH2OH group and subsequent anionic polymerization of ethylene oxide after converting hydroxyl groups into alkoxide groups. Up to DPn ∼ 30 degree of polymerization of POE is equal to [EO]/[bhmim] ratio thus it can easily be controlled. Blending of POE-IL with high-molecular-weight POE leads to significant reduction of crystallinity of POE.

    28. Heterograft copolymers via double click reactions using one-pot technique (pages 6969–6977)

      Aydan Dag, Hakan Durmaz, Emrah Demir, Gurkan Hizal and Umit Tunca

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.23007

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      The synthetic strategy to the various stages of this work is outlined: (i) preparing random copolymers of styrene (St) and p-chloromethylstyrene (CMS) (which is a functionalizable monomer) via nitroxide mediated radical polymerization (NMP); (ii) attachment of anthracene functionality to the preformed copolymer by the o-etherification procedure and then conversion of the remaining [BOND]CH2Cl into azide functionality; (iii) by using double click reactions in one-pot technique, maleimide end-functionalized poly(methyl methacrylate) (PMMA-MI) via atom transfer radical polymerization (ATRP) of MMA and alkyne end-functionalized poly(ethylene glycol) (PEG-alkyne) were introduced onto the copolymer bearing pendant anthryl and azide moieties. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

  3. Note

    1. Top of page
    2. Highlights
    3. Articles
    4. Note
    1. You have free access to this content
      Selective cleavage of acetal bonds in copolymers with polylactide block (pages 6978–6982)

      Stanislaw Sosnowski

      Article first published online: 16 SEP 2008 | DOI: 10.1002/pola.22993

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      A polyester-polyether copolymer containing hydroxyls protected by 1-ethoxyethyl groups was subjected to the reaction of acetal cleavage. It was found that under mild conditions: room temperature, 10-fold excess of methanol, and 1 mol% of AlCl3·6H2O as catalyst, reaction time equal 1 hour, the reaction is quantitative and selective toward acetal groups and not harmful to the ester bonds. The molecular weight of the copolymer was equal to expected one and did not change during threefold prolongation of time of the reaction.

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