A New Scenario of Flow-Induced Shish-Kebab Formation in Entangled Polymer Solutions

Hashimoto, Takeji; Murase, Hiroki; Ohta, Yasuo

doi:10.1021/ma100496g

Cited by 66 publications

(81 citation statements)

References 41 publications

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“…The shish-kebab morphology was first reported in the work by Pennings and Kiel (1965) who observed these structures in a polymeric solution. An explanation to the pathway of shish-kebab formation was recently reported by Hashimoto et al (2010). A factor that can affect the crystallization kinetics is nucleating agents such as organoclays (Lagasse and Maxwell 1976;Jerschow and Janeschitz-Kriegl 1997;Spruiell et al 1996;Nakajima and Yamaguchi 1996;Huo et al 2004;Somwangthanaroj et al 2003).…”

Section: Introductionmentioning

confidence: 84%

Flow-induced crystallization of high-density polyethylene: the effects of shear and uniaxial extension

Derakhshandeh

Hatzikiriakos

2011

Rheol Acta

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The effects of shear, uniaxial extension and temperature on the flow-induced crystallization of two different types of high-density polyethylene (a metallocene and a ZN-HDPE) are examined using rheometry. Shear and uniaxial extension experiments were performed at temperatures below and well above the peak melting point of the polyethylenes in order to characterize their flow-induced crystallization behavior at rates relevant to processing (elongational rates up to 30 s −1 and shear rates 1 to 1,000 s −1 depending on the application). Generally, strain and strain rate found to enhance crystallization in both shear and elongation. In particular, extensional flow was found to be a much stronger stimulus for polymer crystallization compared to shear. At temperatures well above the melting peak point (up to 25 • C), polymer crystallized under elongational flow, while there was no sign of crystallization under simple shear. A modified Kolmogorov crystallization model (Kolmogorov, Bull Akad Sci USSR, Class Sci, Math Nat 1:355-359, 1937) proposed by Tanner and Qi (Chem Eng Sci 64:4576-4579, 2009) was used to describe the crystallization kinetics under both shear and elongational flow at different temperatures.

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Section: Introductionmentioning

confidence: 84%

Flow-induced crystallization of high-density polyethylene: the effects of shear and uniaxial extension

Derakhshandeh

Hatzikiriakos

2011

Rheol Acta

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“…During polymer processing operations, such as fiber spinning, injection molding and extrusion, polymers experience various kinds of flows and crystallization kinetics, and the final morphologies are considerably affected by the external flows . It has been confirmed that when polymers in melts or solutions are crystallized under elongational and/or shear flows a highly anisotropic crystalline architecture termed ‘shish‐kebab’ is formed . The so‐called shish‐kebab structure, consisting of a long central fiber core (shish) and lamellar crystalline structure (kebab) periodically attached to the shish, can substantially influence the final physical and mechanical properties of a component .…”

Section: Introductionmentioning

confidence: 99%

Effects of annealing on the hierarchical crystalline structures and mechanical properties of injection‐molded bars of high‐density polyethylene

Wang

Zhang

Wang

et al. 2013

Polymer International

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The effect of annealing on the microstructural evolution and mechanical properties of high-density polyethylene parts molded via gas-assisted injection molding was investigated using scanning electron microscopy, differential scanning calorimetry, two-dimensional wide-angle X-ray diffraction and tensile testing. The results indicated that a variety of annealing temperatures could induce considerable variations in the hierarchical structures, crystallinity, lamellar thickness and yield stress of the molded bars. According to these results, the annealing temperatures could be divided into three regions. In the low-temperature region of annealing at 80• C, the spatial variation of the superstructure developed along the thickness direction and mechanical properties of the annealed sample were mainly unchanged and similar to those of the original specimen. At 100 and 120• C, the intermediate temperature region of annealing, the thickness of the crystals, degree of orientation and yield stress of annealed samples were greatly improved. Finally, at 127• C, the degree of orientation decreased and yield stress slightly improved, an indication of the high-temperature annealing region being characterized by increasing melting/recrystallization and causing relaxation of oriented molecular chains. A model is proposed to interpret the mechanism of the annealing treatment of the samples at various temperatures.

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“…4, right column) and form shish-kebab-like morphology which is more clearly shown by the inset of the right bottom image. Shish-kebab morphology of crystallizable polymers is usually obtained via strong flow or shear [28][29][30]. Thus it is indeed interesting to achieve shish-kebab-like morphology of PLLA crystals free of any flow.…”

Section: Self-organization Of Oxalamide Compounds In Plla Meltmentioning

confidence: 99%

Tailoring the crystallization behavior of poly(L-lactide) with self-assembly-type oxalamide compounds as nucleators: 1. Effect of terminal configuration of the nucleators

Shen

et al. 2015

European Polymer Journal

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A New Scenario of Flow-Induced Shish-Kebab Formation in Entangled Polymer Solutions

Cited by 66 publications

References 41 publications

Flow-induced crystallization of high-density polyethylene: the effects of shear and uniaxial extension

Flow-induced crystallization of high-density polyethylene: the effects of shear and uniaxial extension

Effects of annealing on the hierarchical crystalline structures and mechanical properties of injection‐molded bars of high‐density polyethylene

Tailoring the crystallization behavior of poly(L-lactide) with self-assembly-type oxalamide compounds as nucleators: 1. Effect of terminal configuration of the nucleators

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