Journal of Polymer Science Part A: Polymer Chemistry

Cover image for Vol. 45 Issue 12

15 June 2007

Volume 45, Issue 12

Pages 2351–2579

  1. Articles

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Notes
    1. Solvent-induced self-organization approach for polymeric architectures of micropores, hexagons and spheres based on polyurethanes prepared via novel melt transurethane methodology (pages 2351–2366)

      P. Deepa and M. Jayakannan

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.22058

      Thumbnail image of graphical abstract

      A novel melt transurethane process is designed and developed for polyurethanes under nonisocyanate and solvent-free conditions. New class of cycloaliphatic polyurethanes were synthesized by the new melt-route, which undergoes selective self-organization in polymer solution to produce polyurethane microporous templates and higher ordered morphologies such as micro or nanometer size polymeric hexagons and spheres. Concentration-dependent solution FTIR and NMR experiments were carried out to trace the mechanistic aspects of the self-organization of polyurethanes. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    2. Novel poly(pyridine imide) with pendent naphthalene groups: Synthesis and thermal, optical, electrochemical, electrochromic, and protonation characterization (pages 2367–2374)

      Der-Jang Liaw, Kun-Li Wang, Feng-Chyuan Chang, Kueir-Rarn Lee and Juin-Yih Lai

      Version of Record online: 4 MAY 2007 | DOI: 10.1002/pola.21997

      Thumbnail image of graphical abstract

      A novel diamine containing a pyridine heterocyclic group and a naphthalene substituent was synthesized with the Chichibabin reaction and used in the preparation of poly (pyridine imide) by direct polycondensation with 4,4′-hexafluoroisopropylidenediphathalic anhydride in N-methyl-2-pyrrolidinone. The poly(pyridine imide) was highly organosoluble and exhibited good thermal stability (temperature of 10% weight loss = 527 °C) in air and high dielectric constants (as high as 4.20 at 1 kHz). The polymer did not show fluorescence in a neutral solution but showed strong green-yellow fluorescence (500 nm) after being protonated with acid.

    3. Synthesis of densely branched poly(methyl methacrylate)s via ATR copolymerization of methyl methacrylate and ethylene glycol dimethacrylate (pages 2375–2386)

      Marc-Henri Bouhier, Peter A. G. Cormack, Susan Graham and David C. Sherrington

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.22001

      Thumbnail image of graphical abstract

      Atom transfer free radical copolymerization of methyl methacrylate and ethylene glycol dimethacrylate, initiated by the phenyl or benzyl esters of 2-bromo-2-methylpropionic acid with CuCl and 2,2% bipyridyl, provides good yields of soluble densely branched PMMAs. Appropriate choice of the EGDMA/initiator feed mole ratio ensures that on average, only one branch unit is incorporated in each primary living polymer chain; such branched rather than crosslinked products are formed.

    4. Novel well-defined star homopolymers and star-block copolymers of poly(n-hexyl isocyanate) by anionic polymerization (pages 2387–2399)

      Georgia Zorba, Marinos Pitsikalis and Nikos Hadjichristidis

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.21952

      Thumbnail image of graphical abstract

      Novel Well-Defined Star Homopolymers and Star-Block Copolymers of Poly(n-hexyl isocyanate) by Anionic Polymerization

    5. Controlled trans-stereospecific polymerization of isoprene with lanthanide(III) borohydride/dialkylmagnesium systems: The improvement of the activity and selectivity, kinetic studies, and mechanistic aspects (pages 2400–2409)

      Michaël Terrier, Marc Visseaux, Thomas Chenal and André Mortreux

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.22002

      Thumbnail image of graphical abstract

      Lanthanide trisborohydrides associated with MgR2 alkylating agents afford efficient initiators for the stereospecific polymerization of isoprene. With neodymium, this system is trans-stereospecific (up to 97.7%) and quasi-living. The molecular weights are controlled by the [Isoprene]/[Nd] ratio, with a polydispersity index lower than 1.6. First-order kinetics can be obtained under standard conditions. A detailed NMR analysis is in accordance with 1,4-propagation.

    6. Synthesis and characterization of conjugated triblock copolymers (pages 2410–2424)

      Xing Xiao, Yaqin Fu, Minghao Sun, Lin Li and Zhishan Bo

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.22003

      Thumbnail image of graphical abstract

      Conjugated triblock copolymers containing hole-transporting polycarbazole segments, electron-transporting polyoxadiazole segments, and blue-light-emitting polyfluorene segments were prepared with a two-step palladium-catalyzed Suzuki polycondensation. An investigation of the photophysical properties indicated that efficient, photoinduced through-bond energy transfer occurred in such triblock copolymer systems.

    7. Star-shaped alkylated poly(glycerol methacrylate) reverse micelles: Synthesis and evaluation of their solubilizing properties in dichloromethane (pages 2425–2435)

      Hui Gao, Marie-Christine Jones, Pankaj Tewari, Maxime Ranger and Jean-Christophe Leroux

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.22004

      Thumbnail image of graphical abstract

      (A) Four, (B) 5-, and (C) 6-arm poly(glycerol methacrylate)s were synthesized by ATRP and partially esterified with either lauroyl or stearoyl chloride (40 or 60 mol % vs. OH content). The resulting amphiphilic star-shaped polymers were shown to self-assemble into inverted micellar structures over a threshold concentration, in dichloromethane. Their ability to accommodate hydrophilic guest molecules was demonstrated through extraction experiments, using Congo red as a model water-soluble dye. All polymers showed high encapsulation efficiencies, with the micelles obtained from the 6-arm polymers achieving the best results. [A color version of the adjacent figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    8. Controlled photopolymerization reactions: The reactivity of new photoiniferters (pages 2436–2442)

      J. Lalevée, M. El-Roz, X. Allonas and J. P. Fouassier

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.22005

      Thumbnail image of graphical abstract

      The character of the process is living. Without a photoinitiator, the dormant species initiate the photopolymerization reaction.

    9. Phototriggered release of photolabile drugs via two-photon absorption-induced cleavage of polymer-bound dicoumarin (pages 2443–2452)

      Sebastian Härtner, Hee-Cheol Kim and Norbert Hampp

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.22007

      Thumbnail image of graphical abstract

      Photocontrolled release of photolabile drugs from polymers for controlled drug delivery is a challenge. For the attachment of drugs to a polymer backbone dicoumarin groups are used as photoactive linkers. Their cyclobutane ring can be specifically cleaved by two-photon absorption and the attached drugs be released. Most drugs contains aromatic groups and often decomposition due to exposure to UV light is observed. For the two-photon absorption induced cleavage of the dicoumarin linkers only light in the visible is required. It is shown, that drugs sensitive to UV light may be released this way without any degradation products to be observed. This concept presents a powerful strategy in polymer design for drug delivery devices.

    10. Initiation of radical polymerization by peroxyacetates: Polymer end-group analysis by electrospray ionization mass spectrometry (pages 2453–2467)

      Michael Buback, Holm Frauendorf, Fabian Günzler and Philipp Vana

      Version of Record online: 14 MAY 2007 | DOI: 10.1002/pola.22008

      Thumbnail image of graphical abstract

      End-groups of poly(methyl methacrylate) from radical polymerization using four peroxyacetates as the initiators were analyzed via electrospray ionization mass spectrometry (ESI-MS). The type and the relative concentration of the radical species, which actually initiate macromolecular growth, are determined. In the majority of cases, these species differ from the primary radicals from thermal decomposition of the peroxyacetates. The pronounced chain-transfer reaction of tert-butoxyl radicals produced from tert-butyl peroxyacetate was utilized to generate small amounts of star polymer by using mesitylene as a co-solvent. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    11. RAFT polymerization of styrenic-based phosphonium monomers and a new family of well-defined statistical and block polyampholytes (pages 2468–2483)

      Ran Wang and Andrew B. Lowe

      Version of Record online: 4 MAY 2007 | DOI: 10.1002/pola.22009

      Thumbnail image of graphical abstract

      The first direct synthesis, via RAFT in water, of statistical and block polyampholytes bearing a permanently cationic phosphonium building block is described. Phosphonium, styrenic-based monomers were prepared and homopolymerized with a trithiocarbonate RAFT CTA in controlled fashion as evidenced by the linear evolution of Mn with conversion and their low polydispersity indices. Statistical copolymerization with 4-vinylbenzoic acid, or block copolymerization using phosphonium macroCTAs, yields the corresponding statistical and block polyampholytes directly, without the need for protection/deprotection protocols or post polymerization modification. We qualitatively demonstrate the ability of these materials to undergo self-assembly as a function of solution pH.

    12. Morphology control in polystyrene/poly(methyl methacrylate) composite latex particles (pages 2484–2493)

      Virginia Herrera, Rosangela Pirri, José M. Asua and Jose R. Leiza

      Version of Record online: 10 MAY 2007 | DOI: 10.1002/pola.21964

      Thumbnail image of graphical abstract

      The presence of block copolymers, produced in situ by means of controlled living radical polymerization during a two-stage seeded polymerization, modified the morphology of polystyrene/poly(methyl methacrylate) composite particles. As the amounts of the block copolymers increased, the particle morphology changed from a hemisphere morphology (a latex without block copolymers) to core–shell morphologies because of a decrease in the polymer–polymer interfacial tension.

    13. New sulfur-centered radicals as photopolymerization initiating species (pages 2494–2502)

      Jacques Lalevée, Lacramioara Zadoina, Xavier Allonas and Jean Pierre Fouassier

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.22012

      Thumbnail image of graphical abstract

      Thiyl radicals can be highly efficient at initiating the polymerization process. New structures have been investigated and compared with classical coinitiators (amines). Tetrazole-derived compounds have been found with similar or higher reactivity and are proposed for practical applications. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

    14. Formation of crystalline inclusion compounds of poly (vinyl chloride) of different stereoregularity with γ-cyclodextrin (pages 2503–2513)

      Gerardo Martínez, Marián A. Gómez, Silvia Villar-Rodil, Leoncio Garrido, Alan E. Tonelli and C. Maurice Balik

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.22014

      Thumbnail image of graphical abstract

      Inclusion compound (ICs) were prepared from γ-cyclodextrin (γ-CD) and two poly (vinylchloride) (PVC) samples with different isotactic content. Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), and solid state 13C-NMR have been used to verify the formation and successfully characterize all inclusion compounds. The coalesced PVC reveals different characteristics specifically for the coalesced PVC sample with higher isotactic content. The results suggest that an irreversible conformational change takes place when PVC forms ICs with a solid host lattice like γ-CD, wich explains, perfectly, the variation in the properties in the coalesced polymer sample, specially the improvement of the global process of thermal degradation.

    15. End-functional poly(methyl methacrylate)s via group transfer polymerization (pages 2514–2531)

      Rudhramyna Gnaneshwar and Swaminathan Sivaram

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.22013

      Thumbnail image of graphical abstract

      Electrophilic termination reactions of silyl ketene acetal ended poly(methyl methacrylate) in group transfer polymerization are employed for the synthesis of end functional poly(methyl methacrylate)s.

    16. Copolymerization of vinyl acetate with 1-octene and ethylene by cobalt-mediated radical polymerization (pages 2532–2542)

      Rayna Bryaskova, Nicolas Willet, Philippe Degée, Philippe Dubois, Robert Jérôme and Christophe Detrembleur

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.21963

      Thumbnail image of graphical abstract

      The cobalt-mediated radical polymerization of vinyl acetate was extended to copolymerization with ethylene and 1-octene. When the copolymerization of vinyl acetate with 1-octene was initiated by 2,2′-azobis(4-methoxy-2,4-dimethyl valeronitrile) in the presence of cobalt(II) bisacetylacetonate [Co(acac)2] or by a poly(vinyl acetate) (PVAc) chain end-capped by Co(acac)2, vinyl acetate was incorporated first and preferentially, so a copolymer with a gradient structure was expected to be formed. Block copolymers of PVAc with a short poly(1-octene) block were also prepared that were precursors of amphiphilic poly(vinyl alcohol-b-octene) copolymers. Ethylene was substituted for 1-octene and polymerized by a PVAc–Co(acac)2 macroinitiator, leading to a copolymer with a very low polydispersity.

    17. Synthesis and characterization of graft copolymers containing poly(p-phenylene) main chains and mesogen-jacketed liquid-crystalline polystyrene side chains (pages 2543–2555)

      Li-Mei Sun, Xing-He Fan, Xiao-Fang Chen, Xiang-Feng Liu and Qi-Feng Zhou

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.22011

      Thumbnail image of graphical abstract

      A series of novel comblike mesogen-jacketed liquid-crystal graft copolymers, poly(p-phenylene)-g-poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} copolymers, have been designed and successfully synthesized by a Yamamoto coupling reaction and atom transfer radical polymerization (ATRP). A study of the polymerization kinetics of ATRP has shown that the molecular weight of the copolymer increases linearly with the conversion of the monomer, whereas the polydispersity remains narrow (≤1.28), indicating that the ATRP of 2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene is well controlled. The results show that the comblike mesogen-jacketed liquid-crystal copolymers can transform into a liquid-crystalline phase ahead of about 20 °C in comparison with the linear ones, and these comblike copolymers should be assigned to a hexatic columnar nematic (ΦHN) phase.

    18. Chitosan-graft-poly(ϵ-caprolactone)s: An optimized chemical approach leading to a controllable structure and enhanced properties (pages 2556–2568)

      Xipeng Guan, Daping Quan, Xintao Shuai, Kairong Liao and Kancheng Mai

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.22015

      Thumbnail image of graphical abstract

      The controlled grafting of poly(ϵ-caprolactone) onto chitosan in a homogeneous medium was carried out with 6-O-triphenylmethyl-chitosan as an intermediate. It was very convenient to adjust the crystallization, solubility, and self-assembly behavior in an aqueous medium of these graft copolymers by changes in the poly(ϵ-caprolactone) chain length and degree of substitution.

  2. Rapid Communications

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Notes
    1. You have free access to this content
      Formation of nanogel aggregates by an amphiphilic cholesteryl-poly(amidoamine) dendrimer in aqueous media (pages 2569–2575)

      Donghui Zhang, Paul D. Hamilton, Jeff L.-F. Kao, Shrinivas Venkataraman, Karen L. Wooley and Nathan Ravi

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.21958

      Thumbnail image of graphical abstract

      The unique properties of dendritic amphiphiles—selfassembly, nano-encapsulation, molecular recognition, and biomimics—have led to a growing interest in the development of new families of these macromolecules. The peripheral hydrophobic modification of commercially available, water-soluble poly(propylene imine) and poly(amidoamine) dendrimers has proven to be a convenient strategy for producing amphiphilic dendrimers in which all or some of the surface groups are hydrophobized.

  3. Notes

    1. Top of page
    2. Articles
    3. Rapid Communications
    4. Notes
    1. You have free access to this content
      Fifty years of living polymers (pages 2576–2579)

      Emile Franta, Thieo Hogen-Esch, Marcel van Beylen and Johannes Smid

      Version of Record online: 9 MAY 2007 | DOI: 10.1002/pola.22006

      Thumbnail image of graphical abstract

      The discovery, published 50 years ago by Michael Szwarc, of what he coined living polymers formed by termination-less anionic polymerization is being commemorated.

SEARCH

SEARCH BY CITATION