Characterization of phase morphology of polymer melts (PP/PE blends) via rheology

2007 ◽  
Vol 105 (4) ◽  
pp. 2294-2298 ◽  
Author(s):  
Krisztina A. Vincze-Minya ◽  
Alois Schausberger
Keyword(s):  
Polymer Melts ◽  
Phase Morphology

scholarly journals Microfluidic characterization of macromolecular liquid–liquid phase separation

Lab on a Chip ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 4225-4234
Author(s):  
Anne Bremer ◽  
Tanja Mittag ◽  
Michael Heymann
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Precise Determination ◽  
Phase Morphology ◽  
Liquid Phase Separation ◽  
Dense Phase ◽  
Liquid Liquid Phase Separation

The microfluidic phase chip allows precise determination of the saturation concentrations of biomolecules that undergo liquid–liquid phase separation while also monitoring the dense-phase morphology.

Direct Equilibration and Characterization of Polymer Melts for Computer Simulations

2015 ◽  
Vol 24 (5) ◽  
pp. 419-431 ◽  
Author(s):  
Livia A. Moreira ◽  
Guojie Zhang ◽  
Franziska Müller ◽  
Torsten Stuehn ◽  
Kurt Kremer
Keyword(s):  
Computer Simulations ◽  
Polymer Melts

In-line ultrasonic characterization of shear dispersion processes of polydisperse fillers in polymer melts

2002 ◽  
Vol 14 (19) ◽  
pp. 4943-4961 ◽  
Author(s):  
Leïla Haïder ◽  
Jacques Tatibouët ◽  
Arnaud Lafaurie ◽  
Laurent Ferry
Keyword(s):  
Polymer Melts ◽  
Ultrasonic Characterization ◽  
Shear Dispersion

A New Technique for Characterizing the Transient Rheological Response of Polymer Melt at High Shear Rates

2000 ◽  
Author(s):  
R. Feng ◽  
Y. Hu
Keyword(s):  
Polymer Melts ◽  
Polymer Melt ◽  
Manufacturing Processes ◽  
Shear Rates ◽  
Rheological Response ◽  
High Shear Rates ◽  
A New Technique ◽  
Polyethylene Melt ◽  
Torsion Bar

Abstract Characterization of the transient rheological response of polymer melts is important for computerized modeling and optimization of the manufacturing processes involving fast polymer melt flow such as injection molding and extrusion. In this paper, a new cone-and-plate rheometer utilizing the Kolsky torsion bar technique is reported. This rheometer can be accelerated to an angular velocity of 1600 rad/s within 100 μs. It enables characterization of the transient response of polymer melts for shear rates up to 104 1/s, temperatures up to 300°C, pressures up to 10 MPa, and shear strains up to 1000%. Experimental data are presented for a low-density polyethylene melt at shear rates between 780 1/s and 6840 1/s. The results show that the shear stress in the material increases not only with the shear rate but also more significantly with the shear strain. The significance of this finding is also discussed.

Phase morphology in block copolymer systems

1994 ◽  
Vol 348 (1686) ◽  
pp. 149-166 ◽  
Keyword(s):  
Block Copolymer ◽  
Microphase Separation ◽  
Boundary Region ◽  
Phase Morphology ◽  
Defect Structures ◽  
Physical Mechanisms ◽  
Triply Periodic ◽  
Single Grain ◽  
Microdomain Structure

Microphase separation in block copolymer systems forms well-defined, periodic structure on the sub-micron length scale. This structure arises from the system striving to satisfy the delicate balance of minimizing the area of contact between incompatible chain segments and maximizing the conformational entropy of the macromolecules. Candidate geometries satisfying these constraints possess intermaterial dividing surfaces (IMDS) of constant mean curvature. These include triply periodic, bicontinuous structures related to minimal surfaces. These structures, recently observed in microphase-separated block copolymer systems, also arise in phase-separated surfactant-water systems, indicating the two phenomena may be driven by similar physical mechanisms. A complete description of block copolymer phase morphology requires characterization of the long-range ordered single grain microdomain structure, the defect structures within grains, and the microstructure of the boundary region between grains. The type of structure observed is sensitive to the architecture, chemical composition, and molecular mass of the copolymers. Thermodynamic treatments using a geometrical description of the IMDS provide a means for probing the physics of phase morphology in block copolymers.

Assessing the practical utility of the hole-pressure method for the in-line rheological characterization of polymer melts

2013 ◽  
Vol 52 (7) ◽  
pp. 661-672 ◽  
Author(s):  
Paulo F. Teixeira ◽  
Loic Hilliou ◽  
José A. Covas ◽  
João M. Maia
Keyword(s):  
Polymer Melts ◽  
Rheological Characterization ◽  
Practical Utility ◽  
Hole Pressure ◽  
Pressure Method

scholarly journals Development of a Rheology Die and Flow Characterization of Gas-Containing Polymer Melts

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3305
Author(s):  
Clemens Kastner ◽  
Dominik Altmann ◽  
Eva Kobler ◽  
Georg Steinbichler
Keyword(s):  
Polymer Melts ◽  
Flow Behavior ◽  
Volumetric Flow Rate ◽  
Thermal Characterization ◽  
Polymer Processing ◽  
Rheological Characterization ◽  
Process Measurement ◽  
Flow Characterization ◽  
Chemical Blowing Agents

We present a novel measurement die for characterizing the flow behavior of gas-containing polymer melts. The die is mounted directly on the injection-molding cylinder in place of the mold cavity and thus enables near-process measurement of viscosity (i.e., under the conditions that would be present were a mold attached). This integration also resolves the issue of keeping gas-containing polymer melts under pressure during measurement to prevent desorption. After thermal characterization of the die, various correction approaches were compared against each other to identify the most suitable one for our case. We conducted measurements using polypropylene in combination with two different chemical blowing agents. Increasing the blowing-agent content to up to 6% revealed an interestingly low influence of gases on melt viscosity, which was confirmed by elongational viscosity measurements. For verification, we compared our results to corresponding measurements taken on a high-pressure capillary rheometer and found that they were in excellent agreement. Our die cannot only be used for rheological characterization. Combined with ultrasound sensors, it provides an innovative way of measuring the volumetric flow rate. This development represents an important step in improving the sustainability of gas-containing polymer processing.

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