Journal of Polymer Science Part B: Polymer Physics

Cover image for Vol. 49 Issue 2

15 January 2011

Volume 49, Issue 2

Pages 89–171

  1. Cover Image

    1. Top of page
    2. Cover Image
    3. Communications
    4. Full Papers
    1. You have free access to this content
      Cover Image, Volume 49, Issue 2 (pages i–ii)

      Version of Record online: 18 FEB 2011 | DOI: 10.1002/polb.22219

      Thumbnail image of graphical abstract

      The cover image shows a glassy polymer disc with a pre-made crack across its center; the disc is loaded so as to create in-plane shear stress at the tips of the crack. When the sample fails, the cracks don't grow in the direction of the pre-made crack. Instead, they initiate in the direction corresponding to the maximum opening stress. As the cracks propagate they change direction to minimize the amount of shear stress at the crack tips. Using systematic studies on shear band formation, Jared Archer and Alan Lesser show that fracture through a shear mechanism is possible in glassy polymers, and are able to relate the behavior to the intrinsic material properties of the polymer. Read the full story on page 103 of this issue.

  2. Communications

    1. Top of page
    2. Cover Image
    3. Communications
    4. Full Papers
    1. Microfluidic channels fabricated on mesoporous electrospun fiber mats: A facile route to microfluidic chips (pages 89–95)

      Eunmin Jo, Min-Cheol Lim, Han-Nah Kim, Hyun-Jong Paik, Young-Rok Kim and Unyong Jeong

      Version of Record online: 23 SEP 2010 | DOI: 10.1002/polb.22147

      Thumbnail image of graphical abstract

      A mat of functionalized mesoporous polystyrene fibers, created by electrospinning, can be attached to a polydimethylsiloxane mold to produce enclosed microfluidic channels for the selective purification of tagged proteins. This simple fabrication process, combined with the high throughput achievable using electrospinning, could greatly contribute to chip-based chromatographic and bioanalytical devices, where low cost and speed are key factors for production.

    2. Effects of microcrystallites on swelling behavior in chemically crosslinked poly(vinyl alcohol) gels (pages 96–102)

      Emiko Otsuka, Shuhei Kudo, Masaaki Sugiyama and Atsushi Suzuki

      Version of Record online: 22 OCT 2010 | DOI: 10.1002/polb.22161

      Thumbnail image of graphical abstract

      Poly(vinyl alcohol) (PVA) gels with different degrees of chemical crosslinks by glutaraldehyde (GA) were prepared. We report the ability to form physical crosslinks by microcrystallites in chemical PVA gels during the drying process after gelation, The effects of microcrystallites on the swelling ratio in rich and poor solvents were discussed in terms of the network microstructure of dried gels using an X-ray diffraction technique and a Fourier transform infrared spectroscopy.

  3. Full Papers

    1. Top of page
    2. Cover Image
    3. Communications
    4. Full Papers
    1. Shear band formation and mode II fracture of polymeric glasses (pages 103–114)

      Jared S. Archer and Alan J. Lesser

      Version of Record online: 11 NOV 2010 | DOI: 10.1002/polb.22159

      Thumbnail image of graphical abstract

      Most of the applications for polymethyl methacrylate and polycarbonate make use of their transparency and impact resistance, but the mechanisms that govern their failure under stress are not fully understood. Study of the failure under tensile and shear stress - normal and parallel to the crack propagation direction respectively - shows that if tensile stress could be actively suppressed the impact resistance of the material would be greatly increased.

    2. Atmospheric plasma treatment of pre-electrospinning polymer solution: A feasible method to improve electrospinnability (pages 115–122)

      Quan Shi, Narendiran Vitchuli, Joshua Nowak, Zhan Lin, Bingkun Guo, Marian Mccord, Mohamed Bourham and Xiangwu Zhang

      Version of Record online: 8 NOV 2010 | DOI: 10.1002/polb.22157

      Thumbnail image of graphical abstract

      Electrospinning is a versatile and reliable method to produce polymer nanofibers, but the challenge lies in balancing rheological behavior, conductivity and surface tension of the spinning solution. Treating a polyethylene oxide solution with atmospheric plasma before electrospinning enhances all these parameters for the process without introducing other components into the resulting nanofibers. Finer and smoother fibers with better crystallinity are achieved.

    3. Tunable microstructures and mechanical deformation in transparent poly(urethane urea)s (pages 123–135)

      R. G. Rinaldi, A. J. Hsieh and M. C. Boyce

      Version of Record online: 8 NOV 2010 | DOI: 10.1002/polb.22128

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      The chemistry of transparent thermoplastic poly (urethane urea)s is modified to control microstructure and tailor mechanical behavior. By modifying the soft segment length and the relative hard segment/soft segment ratio it is possible to adjust the mechanical properties of the material. Such versatility is paramount for the engineering and military applications of this thermoplastic, which including coatings, adhesives, foams, and films for structural retrofitting.

    4. Tuning nanoscopic self-assembly of diblock copolymer blends on a two-dimensional interface (pages 136–143)

      Hsiang-Wei Lu, Jennifer L. Logan, A. E. Hosoi and Shenda M. Baker

      Version of Record online: 7 OCT 2010 | DOI: 10.1002/polb.22126

      Thumbnail image of graphical abstract

      Self-assembly of copolymers gives access to a wide range of different surface morphologies at interfaces between two solutions by varying the molecular composition of the polymer blocks and the concentration of the solutions. Here, in diblock polymer blends, self-assembly of 2D-nanoscale structures can be quantitatively predicted, with no fitting parameters, ultimately enabling the control of the dimensions and the morphologies of the resulting nanostructures.

    5. Microstructure and morphology of self-assembling multiblock poly(ethylene-1-butene)-n copolymers in solution studied by wide-Q small-angle neutron scattering and microscopy (pages 144–158)

      A. Radulescu, D. Schwahn, J. Stellbrink, M. Monkenbusch, L. J. Fetters and D. Richter

      Version of Record online: 19 OCT 2010 | DOI: 10.1002/polb.22158

      Thumbnail image of graphical abstract

      Small-angle neutron scattering and optical microscopy are used to investigate the self-assembling behavior of multiblock copolymers in solution. This approach allows the observation of self-assembly of macro-aggregates arranged in a hierarchical organization from nanometers to tens of micrometers. Such self-assembling copolymers are efficient at reducing the size of wax crystals and thus can be used as alternatives to lubricating oils in the oil industry.

    6. Fractionated crystallization of α- and β-nucleated polypropylene droplets (pages 159–171)

      Deepak S. Langhe, Jong K. Keum, Anne Hiltner and Eric Baer

      Version of Record online: 13 OCT 2010 | DOI: 10.1002/polb.22162

      Thumbnail image of graphical abstract

      Isotactic polypropylene exists in various crystalline forms; the β-form is of particular commercial interest because of its superior impact properties compared to the α-form. Nucleation in the various forms can be achieved by adding heterogenous nuclei or via processing techniques. Here, the effects of two nucleating agents are studied, with three regimes of droplet nucleation identified; which regime applies depends on the concentration of the nucleating agent.

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