A sensitive method to detect very low levels of long chain branching from the molar mass distribution and linear viscoelastic response

2005 ◽  
Vol 49 (6) ◽  
pp. 1503-1520 ◽  
Author(s):  
E. van Ruymbeke ◽  
V. Stéphenne ◽  
D. Daoust ◽  
P. Godard ◽  
R. Keunings ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Molar Mass ◽  
Molar Mass Distribution ◽  
Viscoelastic Response ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Linear Viscoelastic ◽  
Low Levels ◽  
Long Chain ◽  
Sensitive Method

Influence of molar mass distribution and long-chain branching on strain hardening of low density polyethylene

2008 ◽  
Vol 48 (5) ◽  
pp. 479-490 ◽  
Author(s):  
Florian J. Stadler ◽  
Joachim Kaschta ◽  
Helmut Münstedt ◽  
Florian Becker ◽  
Michael Buback
Keyword(s):  
Strain Hardening ◽  
Mass Distribution ◽  
Molar Mass ◽  
Molar Mass Distribution ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Long Chain

scholarly journals Rheological Behavior of Blends of Metallocene Catalyzed Long-Chain Branched Polyethylenes. Part I: Shear Rheological and Thermorheological Behavior

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 328
Author(s):  
Chuangbi Chen ◽  
Mehdihasan I. Shekh ◽  
Shuming Cui ◽  
Florian J. Stadler
Keyword(s):  
Mass Distribution ◽  
Rheological Behavior ◽  
Molar Mass ◽  
Complexity Analysis ◽  
Relaxation Times ◽  
Molar Mass Distribution ◽  
Long Chain Branching ◽  
Base Materials ◽  
Thermorheological Complexity ◽  
Long Chain

Long-chain branched metallocene-catalyzed high-density polyethylenes (LCB-mHDPE) were solution blended to obtain blends with varying degrees of branching. A high molecular LCB-mHDPE was mixed with low molecular LCB-mHDPE at varying concentrations. The rheological behavior of those low molecular LCB-mHDPE is similar but their molar mass and molar mass distribution are significantly different. Those blends were characterized rheologically to study the effects of concentration, molar mass distribution, and long-chain branching level of the low molecular LCB-mHDPE. Owing to the ultra-long relaxation times of the high molecular LCB-mHDPE, the blends exhibited a clearly more long-chain branched behavior than the base materials. The thermorheological complexity analysis showed an apparent increase in the activation energies Ea determined from G′, G″, and especially δ. Ea(δ), which for LCB-mHDPE is a peak function, turned out to produce even more pronounced peaks than observed for LCB-mPE with narrow molar mass distribution and also LCB-mPE with broader molar mass distribution. Thus, it is possible to estimate the molar mass distribution from the details of the thermorheological complexity.

scholarly journals Rheological Behavior of Blends of Metallocene Catalyzed Long-Chain Branched Polyethylenes. Part I: Shear Rheological and Thermorheological Behavior

2020 ◽  
Author(s):  
Chuangbi Chen ◽  
Mehdihasan I. Shekh ◽  
Shuming Cui ◽  
Florian J. Stadler
Keyword(s):  
Mass Distribution ◽  
Rheological Behavior ◽  
Molar Mass ◽  
Relaxation Times ◽  
Molar Mass Distribution ◽  
Long Chain Branching ◽  
Base Materials ◽  
Thermorheological Complexity ◽  
Peak Function ◽  
Long Chain

Long-chain branched metallocene-catalyzed high-density polyethylenes (LCB-mHDPE) were solution blended to obtain blends with varying degrees of branching. A high molecular LCB-mHDPE was mixed with low molecular LCB-mHDPE are varying concentrations, whose rheological behavior is similar but whose molar mass and molar mass distribution is significantly different. Those blends were characterized rheologically to study the effects of concentration, molar mass distribution, and long-chain branching level of the low molecular LCB-mHDPE. Owing to the ultra-long relaxation times of the high molecular LCB-mHDPE, the blends started behaving clearly more long-chain branched than the base materials. The thermorheological complexity showed an apparent increase in the activation energies Ea determined from G’, G”, and especially δ. Ea(δ), which for LCB-mHDPE is a peak function, turned out to produce even more pronounced peaks than observed for regular LCB-mPE and also LCB-mPE with broader molar mass distribution. Thus, it is possible to estimate the molar mass distribution from the details of the thermorheological complexity.

scholarly journals Rheological Behavior of Blends of Metallocene Catalyzed Long-Chain Branched Polyethylenes. Part I: Shear Rheological and Thermorheological Behavior

2021 ◽  
Author(s):  
Chuangbi Chen ◽  
Mehdihasan I. Shekh ◽  
Shuming Cui ◽  
Florian J. Stadler
Keyword(s):  
Mass Distribution ◽  
Rheological Behavior ◽  
Molar Mass ◽  
Relaxation Times ◽  
Molar Mass Distribution ◽  
Long Chain Branching ◽  
Base Materials ◽  
Thermorheological Complexity ◽  
Peak Function ◽  
Long Chain

Long-chain branched metallocene-catalyzed high-density polyethylenes (LCB-mHDPE) were solution blended to obtain blends with varying degrees of branching. A high molecular LCB-mHDPE was mixed with low molecular LCB-mHDPE are varying concentrations, whose rheological behavior is similar but whose molar mass and molar mass distribution is significantly different. Those blends were characterized rheologically to study the effects of concentration, molar mass distribution, and long-chain branching level of the low molecular LCB-mHDPE. Owing to the ultra-long relaxation times of the high molecular LCB-mHDPE, the blends started behaving clearly more long-chain branched than the base materials. The thermorheological complexity showed an apparent increase in the activation energies Ea determined from G’, G”, and especially δ. Ea(δ), which for LCB-mHDPE is a peak function, turned out to produce even more pronounced peaks than observed for regular LCB-mPE and also LCB-mPE with broader molar mass distribution. Thus, it is possible to estimate the molar mass distribution from the details of the thermorheological complexity.

scholarly journals Influence of the Molar Mass on Long-Chain Branching of Polypropylene

Polymers ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 442 ◽  
Author(s):  
Florian Kamleitner ◽  
Bernadette Duscher ◽  
Thomas Koch ◽  
Simone Knaus ◽  
Klaus Schmid ◽  
...  
Keyword(s):  
Molar Mass ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Long Chain

Influence of long-chain branching on linear viscoelastic flow properties and dielectric relaxation of polycarbonates

Polymer ◽  
2004 ◽  
Vol 45 (8) ◽  
pp. 2803-2812 ◽  
Author(s):  
Chenyang Liu ◽  
Chaoxu Li ◽  
Peng Chen ◽  
Jiasong He ◽  
Qingrong Fan
Keyword(s):  
Dielectric Relaxation ◽  
Viscoelastic Flow ◽  
Flow Properties ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Linear Viscoelastic ◽  
Long Chain

Detection of Low Levels of Long-Chain Branching in Polyolefins

2008 ◽  
Author(s):  
T. P. Karjala ◽  
R. L. Sammler ◽  
M. A. Mangnus ◽  
L. G. Hazlitt ◽  
M. S. Johnson ◽  
...  
Keyword(s):  
Chain Branching ◽  
Long Chain Branching ◽  
Low Levels ◽  
Long Chain

Detection of low levels of long-chain branching in polydisperse polyethylene materials

2010 ◽  
Vol 119 (2) ◽  
pp. 636-646 ◽  
Author(s):  
Teresa P. Karjala ◽  
Robert L. Sammler ◽  
Marc A. Mangnus ◽  
Lonnie G. Hazlitt ◽  
Mark S. Johnson ◽  
...  
Keyword(s):  
Chain Branching ◽  
Long Chain Branching ◽  
Low Levels ◽  
Long Chain
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