Journal of Polymer Science Part B: Polymer Physics

Cover image for Vol. 50 Issue 23

1 December 2012

Volume 50, Issue 23

Pages i–ii, 1597–1662

  1. Cover Image

    1. Top of page
    2. Cover Image
    3. Full Papers
    1. You have free access to this content
      Cover Image, Volume 50, Issue 23 (pages i–ii)

      Version of Record online: 25 OCT 2012 | DOI: 10.1002/polb.23210

      Thumbnail image of graphical abstract

      With the advent of new techniques, it is now possible to compatibilize nanoscopic particles with polymers. The effect of such particles on the macroscopically observed properties of the mixture can be predicted. At these length scales, due to the large surface-to-volume ratio of the nanoparticles, the polymer-nanoparticle interface plays a crucial role on enhanced properties. A systematic scanning of nanoparticle size and interaction strength by molecular dynamics simulations displays how altered dynamics at the interface modifies mechanical properties, as presented on page 1653 by Canan Atilgan and colleagues. A thermodynamical analysis indicates that structural inhomogeneities collectively organize, leading to the observed material behavior.

  2. Full Papers

    1. Top of page
    2. Cover Image
    3. Full Papers
    1. Nanoindentation, nanoscratch, and nanotensile testing of poly(vinylidene fluoride)-polyhedral oligomeric silsesquioxane nanocomposites (pages 1597–1611)

      Fanlin Zeng, Yizhi Liu, Yi Sun, Enlai Hu and Yu Zhou

      Version of Record online: 14 SEP 2012 | DOI: 10.1002/polb.23159

      Thumbnail image of graphical abstract

      Because of its strong piezoelectricity, poly(vinylidene difluoride) (PVDF) is widely used in applications including actuators, transducers, and smart sensors. However, neat PVDF cannot always meet the necessary mechanical property requirements. To improve these properties, nanocomposites were prepared by incorporating fluorinated polyhedral oligomeric silsesquioxanes (FP-POSS) into the PVDF matrix. Nanoindentation, nanoscratch, and nanotensile tests were carried out to study the influence of different contents of FP-POSS on the key static and dynamic mechanical properties.

    2. High-efficiency polymer solar cells based on phenylenevinylene copolymer with BF2-azopyrrole complex and CN-PC70BM with solvent additive (pages 1612–1618)

      Surya Prakash Singh, CH Pavan Kumar, G. D. Sharma, J. A. Mikroyannidis, Manjeet Singh and Rajnish Kurchania

      Version of Record online: 28 SEP 2012 | DOI: 10.1002/polb.23160

      Thumbnail image of graphical abstract

      Polymer solar cells hold promise for generating renewable energy at low cost, but the low efficiency of the cells at converting light to power is a problem. Here, a processing additive (chloronaphthalene) in the active layer and control of the drying conditions are shown to provide effective means to control both the surface roughness and interpenetrating networks. This enhances exciton dissociation into charge carriers, charge transportation, and collection to more than double the power conversion efficiency.

    3. Decoupling of reactions in reactive polymer blending for nanoscale morphology control (pages 1619–1629)

      Prashant A. Bhadane, John Cheng, Maria D. Ellul and Basil D. Favis

      Version of Record online: 14 SEP 2012 | DOI: 10.1002/polb.23163

      Thumbnail image of graphical abstract

      Reactive polymer blending is widely used to carry out in situ reactive grafting and crosslinking reactions. Very few studies in the literature have focused on processing multiphase systems for simultaneous control of complex multiple effects such as morphology, interfacial reaction, and dynamic crosslinking. This work systematically studies and demonstrates the role of temperature and mixing sequence in decoupling these effects. This understanding allows for nanoscale morphology control in these systems.

    4. Strain-induced crystallization of natural rubber with high strain rates (pages 1630–1637)

      Baijin Zhao, Nan Tian, Yanpin Liu, Tingzi Yan, Weiqing Zhou, Liangbin Li, Yingui Zhou, Gengsheng Weng and Guangsu Huang

      Version of Record online: 21 SEP 2012 | DOI: 10.1002/polb.23172

      Thumbnail image of graphical abstract

      Strain-induced crystallization in natural rubber (NR) is responsible for the self-reinforcement character that gives its excellent mechanical properties. By stretching NR to a fixed strain in a step model, it was found that the increase in crystallinity resulted from the increase of the number of new crystallites rather than the growth of the crystal size during the crystallization after the cessation of stretch. Moreover, an Avrami index of 1 was attributed to a homogenous nucleation taking place during this process.

    5. Anisotropic thermal transport in a crosslinked polyisoprene rubber subjected to uniaxial elongation (pages 1638–1644)

      David Nieto Simavilla, Jay D. Schieber and David C. Venerus

      Version of Record online: 1 OCT 2012 | DOI: 10.1002/polb.23173

      Thumbnail image of graphical abstract

      To examine the validity of the stress-thermal rule for large deformations of natural rubber, as well as the apparent universality of the stress-thermal coefficient, anisotropic thermal conduction in a crosslinked polyisoprene subjected to uniaxial elongation is studied. Using an optical technique based on Forced Rayleigh Scattering, components of the thermal diffusivity tensor parallel and perpendicular to the direction of elongation have been measured as a function of elongation ratio. It is observed that the stress-thermal rule is valid for deformation levels at which the stress-optic rule fails.

    6. Electrical conductivity of poly(ethylene terephthalate)/expanded graphite nanocomposites prepared by in situ polymerization (pages 1645–1652)

      S. Paszkiewicz, A. Szymczyk, Z. Špitalský, M. Soccio, J. Mosnáček, T. A. Ezquerra and Z. Rosłaniec

      Version of Record online: 28 SEP 2012 | DOI: 10.1002/polb.23176

      Thumbnail image of graphical abstract

      Poly(ethylene terephthalate) (PET)/expanded graphite (EG) nanocomposites were prepared by an intensive EG dispersion process in monomer followed by in situ polymerization. The obtained nanocomposites exhibit conducting behavior with a low percolation threshold of ≈0.05 wt %, and the relationship between the preparation method, morphology, and electrical conductivity was studied. The low percolation threshold and relatively high electrical conductivity are attributed to the high aspect ratio, large surface area, and uniform dispersion of the expanded EG in the PET matrix.

    7. On modifying properties of polymeric melts by nanoscopic particles (pages 1653–1662)

      Canan Atilgan, Ibrahim Inanc and Ali Rana Atilgan

      Version of Record online: 5 OCT 2012 | DOI: 10.1002/polb.23179

      Thumbnail image of graphical abstract

      Computer modeling and simulations have had an increasing role in understanding and controlling the underlying mechanism of property changes and enhancements in polymer nanocomposites. In this work, a systematic scanning of nanoparticle size and interaction strength by molecular dynamics simulations relates interface dynamics to enhancement of mechanical properties. Altered dynamics at the interface affects long time scales, in turn modifying mechanical properties. Structural inhomogeneities collectively organize leading to the observed material behavior.