Journal of Polymer Science Part B: Polymer Physics

Cover image for Vol. 51 Issue 12

15 June 2013

Volume 51, Issue 12

Pages i–ii, 927–997

  1. Cover Image

    1. Top of page
    2. Cover Image
    3. Full Papers
    1. You have free access to this content
      Cover Image, Volume 51, Issue 12 (pages i–ii)

      Article first published online: 8 MAY 2013 | DOI: 10.1002/polb.23308

      Thumbnail image of graphical abstract

      Organic π-conjugated polymers such as PPV and MEH-PPV are widely investigated for their high luminescence efficiency, facile processing, and electronic tenability. The hole and electron transport properties have been shown to be markedly different for cis conformations of PPV derivatives in comparison to the trans ones. In the paper by Iffat H. Nayyar, Enrique R. Batista, Sergei Tretiak, Avadh Saxena, Darryl L. Smith, and Richard L. Martin on page 935, the effect of the presence of trans and cis types of conformational defects and alkoxy side groups on the localization of polaronic excitations in PPV is explored using density functional theory calculations.

  2. Full Papers

    1. Top of page
    2. Cover Image
    3. Full Papers
    1. Effect of thermal history on the ionic conductivity of block copolymer electrolytes (pages 927–934)

      Scott A. Mullin, Alexander A. Teran, Rodger Yuan and Nitash P. Balsara

      Article first published online: 9 APR 2013 | DOI: 10.1002/polb.23290

      Thumbnail image of graphical abstract

      Strong temperature-history dependent effects are demonstrated for series of lamellar and cylindrical block copolymer electrolytes. Before annealing, samples typically exhibit higher conductivities and weak molecular weight dependencies for both morphologies. The onset of long-range structural order, as is expected to develop during annealing processes, may result in disconnection or increased tortuosity of the conductive phase across grain boundaries.

    2. Effect of trans- and cis-isomeric defects on the localization of the charged excitations in π-conjugated organic polymers (pages 935–942)

      Iffat H. Nayyar, Enrique R. Batista, Sergei Tretiak, Avadh Saxena, Darryl L. Smith and Richard L. Martin

      Article first published online: 9 APR 2013 | DOI: 10.1002/polb.23291

      Thumbnail image of graphical abstract

      Organic π-conjugated polymers such as poly(p-phenylene vinylene) (PPV) and poly[2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV) are widely investigated for their high luminescence efficiency, facile processing, and electronic tunability. The hole- and electron-transport properties have been shown to be markedly different for cis conformations of PPV derivatives in comparison to the trans ones. In this contribution, the effect of the presence of trans and cis types of conformational defects and alkoxy side groups on the localization of polaronic excitations in PPV is explored using density functional theory calculations.

    3. Correlation of charge transport with structural order in highly ordered melt-crystallized poly(3-hexylthiophene) thin films (pages 943–951)

      Chetan R. Singh, Gaurav Gupta, Ruth Lohwasser, Sebastian Engmann, Jens Balko, Mukundan Thelakkat, Thomas Thurn-Albrecht and Harald Hoppe

      Article first published online: 23 APR 2013 | DOI: 10.1002/polb.23297

      Thumbnail image of graphical abstract

      A series of well-defined P3HT homopolymers of different molecular weight (MW) was investigated for structure-property relationships in diode configuration. A unique correlation has been revealed between a MW determined structural parameter, the long period, and an electronic property, the charge mobility. In compliance with the long period, the charge mobility at first increased with the lateral extension of P3HT chains for smaller MWs before decreasing again at the onset of chain folding for higher MWs.

    4. Extruder-made TPO nanocomposites. II. Effect of maleated poly(propylene)/organoclay ratio on morphology and thermal expansion behavior (pages 952–965)

      Rajkiran R. Tiwari, Douglas L. Hunter and Donald R. Paul

      Article first published online: 27 MAR 2013 | DOI: 10.1002/polb.23289

      Thumbnail image of graphical abstract

      The high thermal expansion of thermoplastic olefin blends makes them unsuitable for some applications especially in the automotive industry. Significant reduction in the coefficient of linear thermal expansion (CTE) is shown in the presence of montmorillonite (MMT) dispersion facilitated by polypropylene-grafted-maleic anhydride (PP-g-MA). CTE decreases in flow and transverse direction and increases in normal direction with no change in bulk CTE. Overall, stiffness and toughness improved with no change in bulk CTE in the presence of MMT and PP-g-MA.

    5. Structural relaxation behavior of strain hardened shape memory polymer fibers for self-healing applications (pages 966–977)

      Pengfei Zhang and Guoqiang Li

      Article first published online: 22 APR 2013 | DOI: 10.1002/polb.23295

      Thumbnail image of graphical abstract

      Shape memory polyurethane fiber is programmed by cyclic load. This cold-drawing programming process leads to a less disordered nonequilibrium state from a high disordered equilibrium state, and stored strain energy. The nonequilibrium structure provides the programmed fiber a potential driving force for shape recovery, and the stored strain energy enables it to have the ability to close a wide-opened crack. After long-term relaxation, the self-healing ability of the programmed fiber is predicted theoretically.

    6. Interphase/interface modification on the dielectric properties of polycarbonate/poly(vinylidene fluoride-co-hexafluoropropylene) multilayer films for high-energy density capacitors (pages 978–991)

      Zheng Zhou, Joel Carr, Matthew Mackey, Kezhen Yin, Donald Schuele, Lei Zhu and Eric Baer

      Article first published online: 22 APR 2013 | DOI: 10.1002/polb.23296

      Thumbnail image of graphical abstract

      To improve the energy density of polymer films used for capacitors, a high breakdown strength insulating polymer, polycarbonate (PC), is microlayered with a high dielectric constant polymer, polyvinylidene fluoride (PVDF). The dielectric breakdown strength, displacement–electric field hysteresis, and dielectric spectroscopy of 65-layer PC/tie/Poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)] are investigated with various tie materials. The PC/PMMA/P(VDF-HFP) films exhibits a 25% enhancement in breakdown properties, 50% higher energy density, 40% smaller hysteresis loop areas, and orders of magnitude slower ion migration relative to the 33-layer PC/P(VDF-HFP) control.

    7. Time-resolved spectroscopy study of donor–acceptor-type copolymers in a monodisperse system: The effect of ratio between the acceptor and the donor (pages 992–997)

      Ying-Hui Wang, Li-Jing Gong, Wen-Yue Dong, Ping Lu, Zhi-Hui Kang, Tian-Hao Huang, Yu-Guang Ma and Han-Zhuang Zhang

      Article first published online: 30 APR 2013 | DOI: 10.1002/polb.23298

      Thumbnail image of graphical abstract

      The ratio between the donor and the acceptor (PCFBT0.5 and PCFBT0.1) influences the photoexcitation dynamics of the copolymer. When the number of the donor is equal to that of the acceptor in one repeat, intrachain charge transfer can occur in the relaxation of excited PCFBT0.5. When the number of the donor is larger than that of the acceptor in one repeat, the localized exciton relaxation is dominant in the relaxation of excited PCFBT0.1.

SEARCH

SEARCH BY CITATION