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Showing 1 to 12 of 12 for “"flow-induced crystallization"”.
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Flow Induced Crystallization of Polyethylene Fibers From Solution
… of a polyethylene fiber in the Poiseuille flow geometry. Features of an earlier study using the surface growth method to produce polyethylene fibers in Couette geometry are also included in the discussion. Fiber growth is initiated from a polyethylene seed inserted into a capillary tube and …
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A study of transient flow-induced crystallization of polymer melts
Flow-induced crystallization of several polymer systems has been studied using a four-roll mill device, coupled with optical polarimetry, to provide an in-situ technique for monitoring the transformation kinetics both during and following flow. The use of a crystallizable droplet phase, suspended …
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A study of flow-induced crystallization in two-phase polymer melts
The effects of shearing and elongational flows on flow induced crystallization in polymer melts were investigated for the two-phase system of high molecular weight polyethylene suspended in a linear low density polyethylene carrier phase. Shearing flow was produced by a counter-rotating couette …
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A Microstructural Model for Flow -Induced Crystallization With Applications to the Simulation of Polymer Processes
We suggest that our model can be used as an optimization tool for melt spinning, enabling prediction of the final fiber properties through the radial variation of the tensile stress and microstructure, as well as other polymer processes involving FIC.
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Molecular dynamics modeling of orientation-induced nucleation in short alkanes : toward molecular modeling of flow-induced crystallization in polymers
The enhancement of the primary flow-induced nucleation rate in short chain alkanes (C20 and C150) has been examined for different levels of orientation by atomistic molecular dynamics simulations. The nucleation rate has been found to change drastically by varying average molecular orientation and …
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Structure Formation and Crystallization in Two-Phase Polymer Blend Flows (Fibers, Polyethylene, Polypropylene)
Flow induced crystallization of high density polyethylene and polypropylene has been studied in a two-phase flow system using linear low density polyethylene as the carrier phase. Extensional stresses were generated under slow flow conditions by either of two methods: one involving flow past a …
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Crystallization kinetics of polymer melts in extensional flow
A technique to study the kinetics of flow-induced crystallization of polymers in extensional flow has been developed which uses a 4-Roll Mill. The kinetics of a High Density Polyethylene were found to be well described by the Avrami treatment, indicated that the crystallization occurred by sporadic …
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Oriented polymer crystal growth from flowing solutions
The kinetics of dilute solution flow-induced crystallization in a tubular flow geometry have been quantified for several polymer systems using digital image processing to observe and monitor the birefringence of the crystallizing fiber. Three molecular weights of polyethylene were studied in 0.01 …
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Reactive modification and crystallization behavior of foamed poly(butylene terephthalate)
… data was based on fundamentals of extrusion, crystallization mechanisms, as well as information on reactivity and tendency toward degradation of PBT. As a preliminary study, the extrusion foaming behavior of a commercial linear semi-crystalline PBT with a chemical blowing agent (CBA) was …
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Molecular simulation of nucleation from flowing polymer melts
During processing, flow drastically accelerates the kinetics of polymer crystallization, altering the morphology and properties of the resulting material The earliest stage of flow-induced crystallization, known as flow-enhanced nucleation (FEN), is challenging to study experimentally due to the …
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Polymer Crystallization: Micro- and Nano- Filler Effects on Isotactic Polypropylene
… studies about the effects of fillers on the crystallization behavior of composites are of great interest. Nucleated crystallization has been the subject of several studies over the last 50 years or so [Cormia et al. 1962, Binsbergen 1970, Mercier 1990]. In the relative simple case of …
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Processing-driven structuring of melt compounded polymer-based systems
L'abstract è presente nell'allegato / the abstract is in the attachment