Flow induced crystallization prevents melt fracture of HDPE in uniaxial extensional flow
نویسندگان
چکیده
منابع مشابه
Extensional-flow-induced crystallization of isotactic polypropylene
A filament stretching extensional rheometer with a custom-built oven was used to investigate the effect of uniaxial flow on the crystallization of polypropylene. Prior to stretching, samples were heated to a temperature well above the melt temperature to erase their thermal and mechanical histories and the Janeschitz-Kriegl protocol was applied. The samples were stretched at extension rates in ...
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Flow-induced crystallization is investigated through short-term shear flow experiments on poly(1butene) in the RheoDSC device. We demonstrate that the DSC signal shows contributions from spherulitic morphology in the center of the sample and oriented structures at the edge of the sample, the latter being induced by edge effects at the free surface. It is shown that, although small in terms of v...
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A standard Instron testing machine, in which crosshead displacement varies linearly with time was modified so that crosshead displacement varies exponentially with time. This change permits testing at constant Hencky strain rate (c = fi/8), which provides a constant stretch history for both simple extensional flow and strip biaxial extensional flow. This results in a visualization of the steady...
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From an analysis of tangent spherical drops in straining flow, Baldessari and Leal conclude that the drop-scale internal circulation, driven by the ambient flow, has a negligible influence on the drainage of the thin liquid film between drops under small-deformation conditions [F. Baldessari, L.G. Leal, J. Colloid Interface Sci. 289 (2005) 262]. However, their conclusion is incorrect as explain...
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We make use of a specially synthesized linear high density polyethylene with a bimodal molecular weight distribution (MWD) to demonstrate that it is possible to produce a suspension of extended-chain (shish) crystals only. Such a suspension can be generated at high temperatures, above but close to the equilibrium melting temperature of the unconstrained extended-chain crystals (T(m)(0)=141.2 de...
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ژورنال
عنوان ژورنال: Journal of Rheology
سال: 2018
ISSN: 0148-6055,1520-8516
DOI: 10.1122/1.5038393