Melt rheology of long-chain-branched polypropylenes

Sugimoto, Masataka; Suzuki, Yasuhiro; Hyun, Kyu; Ahn, Kyung Hyun; Ushioda, Tsutomu; Nishioka, Akihiro; Taniguchi, Takashi; Koyama, Kiyohito

doi:10.1007/s00397-005-0065-z

Cited by 87 publications

(60 citation statements)

References 56 publications

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“…shape whereas the branched PP melt displays a "backward tilted stress" shape [37,94]. The "forward tilted stress" shape was observed in the case of polymer melts and solutions with a linear chain structure whereas the "backward tilted stress" shape was observed for suspensions and polymer melts with branched chains [94].…”

Section: Nonlinear Shear Stress Waveformsmentioning

confidence: 99%

“…FT-Rheology was used for various complex fluids, such as polymer melts [34][35][36][37][38][39][40][41][42], polymer solutions [43,44], polymer blends [45][46][47], block copolymers [6,48,49] and dispersed systems [5,32,45,50]. Leblanc et al [51][52][53][54][55][56][57][58][59][60] systematically investigated various industrial elastomers and rubber materials with FT-Rheology, including EPDM rubber(ethylene propylene diene M-class rubber) [51][52][53], poly (vinyl chloride) (PVC)/ green coconut fiber (GCF) composites [54], carbon black filled rubber compounds [52,[55][56][57][58], natural rubber [59], polybutadiene rubber (BR) and styrene-butadiene rubber (SBR) [53,56], and thermoplastic vulcanizates (TPVs).…”

Section: Historical Survey Of Laosmentioning

confidence: 99%

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A review of nonlinear oscillatory shear tests: Analysis and application of large amplitude oscillatory shear (LAOS)

Hyun

Wilhelm

Klein

et al. 2011

Progress in Polymer Science

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1,239

699

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Dynamic oscillatory shear tests are common in rheology and have been used to investigate a wide range of soft matter and complex fluids including polymer melts and solutions, block copolymers, biological macromolecules, polyelectrolytes, surfactants, suspensions, emulsions and beyond. More specifically, Small Amplitude Oscillatory Shear (SAOS) tests have become the canonical method for probing the linear viscoelastic properties of these complex fluids because of the firm theoretical background [1][2][3][4] and the ease of implementing suitable test protocols. However, in most processing operations the deformations can be large and rapid: it is therefore the nonlinear material properties that control the system response. A full sample characterization thus requires well-defined nonlinear test protocols. Consequently there has been a recent renewal of interest in exploiting Large Amplitude Oscillatory Shear (LAOS) tests to investigate and quantify the nonlinear viscoelastic behavior of complex fluids. In terms of the experimental input, both LAOS and SAOS require the user to select appropriate ranges of strain amplitude (γ 0 ) and frequency (ω). However, there is a distinct difference in the analysis of experimental output, i.e. the material response. At sufficiently large strain amplitude, the material response will become nonlinear in LAOS tests and the familiar material functions used to quantify the linear behavior in SAOS tests are no longer sufficient. For example, the definitions of the linear viscoelastic moduli G΄(ω) and G˝(ω) are based inherently on the assumption that the stress response is purely sinusoidal (linear). However, a nonlinear stress response is not a perfect sinusoid and therefore the viscoelastic moduli are not uniquely defined; other methods are needed for quantifying the nonlinear material response under LAOS deformation. In the present review article, we first summarize the typical nonlinear responses observed with complex fluids under LAOS deformations. We then introduce and critically compare several methods that quantify the nonlinear oscillatory stress response. We illustrate the utility and sensitivity of these protocols by investigating the nonlinear response of various complex fluids over a wide range of frequency and amplitude of deformation, and show that LAOS characterization is a rigorous test for rheological models and 3 advanced quality control.

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Section: Nonlinear Shear Stress Waveformsmentioning

confidence: 99%

Section: Historical Survey Of Laosmentioning

confidence: 99%

A review of nonlinear oscillatory shear tests: Analysis and application of large amplitude oscillatory shear (LAOS)

Hyun

Wilhelm

Klein

et al. 2011

Progress in Polymer Science

Self Cite

1,239

699

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show abstract

“…Münstedt et al provided excellent work on this topic [152,156,157] among other works. [128,130,158,159] However, the strain hardening in extension can also be a result of very small amount of high-molecular-weight materials in linear polymers. [160,161] The technique is not very sensitive to LCBD either.…”

Section: Extension Rheology (Strain-harding Effect)mentioning

confidence: 99%

“…Short branches with a chain length between M e and M c also have effects on this dependency. [159] Münstedt and co-workers. studied the influence of molecular structure of POs (linear and long-chain branched PE and PP) with a damping function in detail.…”

Section: Characteristic Relaxation Time and Damping Functionmentioning

confidence: 99%

A Comprehensive Review on Controlled Synthesis of Long‐Chain Branched Polyolefins: Part 3, Characterization of Long‐Chain Branched Polymers

Liu

Wang

et al. 2016

Macro Reaction Engineering

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Synthesis and characterization of long-chain branched polyolefins has been an important research topic for both academic and industrial researchers for many decades. This is particularly true since the discovery and successful commercialization of the constrained geometry catalyst systems in 1990s. The type of single site catalysts allows control in the synthesis and the precision in the characterization. Long-chain branched polyolefins exhibit improved melt processability, such as higher melt strength and better shear thinning, compared to their linear counterparts having the same molecular weight and distribution. In the previous papers, the catalyst systems and reaction conditions for the controlled synthesis of long-chain branched polyolefins have been reviewed. This paper aims at summarizing the literatures pertinent to the precise characterization of long-chain branched polyolefins. The major methods of long-chain branching characterization include: nuclear magnetic resonance, gel permeation chromatography, rheometry, dynamical mechanical analysis, differential scanning calorimetry, neutron scattering, and Fourier transform infrared spectroscopy. Recent progresses of these characterization methods, as well as their advantages and limitations, have been discussed in details.

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“…7) On the other hand, some heterogeneous polymeric systems show anomalous strain rate dependence of strain-hardening. [8][9][10][11] Elongational viscosity of rubber shows independence of strain-hardening from strain rate since stress-strain curves at various strain rates converge on one line. The mechanism of enhancement of strainhardening is presumably related to elasticity of SBS.…”

Section: Measurementsmentioning

confidence: 99%

The Influence of Heat Treatment on Uniaxial Elongational Flow Behavior of PS/SBS Blends

Nishioka

Minegishi

Takahashi

et al. 2006

J. Soc. Rheol., Jpn

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Uniaxial elongational flow behavior was examined for polystyrene(PS)/styrene-butadiene-styrene(SBS) triblock copolymer by using a Meissner type rheometer under uniaxial elongational flow at constant strain rates. The mixtures of PS and SBS were prepared by means of a solution blending method. Pure PS did not exhibit strain-hardening. Elongational viscosity was quite similar among the mixtures of PS/SBS without heat treatment. However, large enhancement of strain-hardening was observed for PS/SBS blends treated at temperatures higher than 220 °C, and the magnitude of enhancement reached ten times or more. To analyze the cause of the enhancement of strain-hardening, we examined pure SBS itself using a combination of uniaxial elongation and FT-IR spectroscopy. Change in uniaxial elongational flow behavior, i.e., from strain-softening to strain-hardening, was observed corresponding to heat treatment temperatures. From FT-IR spectroscopy of SBS treated at various temperatures, the correlation between enhancement of strain-hardening and crosslinking of butadiene was obtained. From shear stress relaxation measurement of PS/SBS(90/ 10) treated at 260 °C for 60 min, convergence of relaxation modulus was observed in a strain range of γ 2 at long times. Thus, the increase of strain-hardening of PS/SBS blends treated at high temperatures is likely to result from affine deformation of crosslinked SBS component.

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Melt rheology of long-chain-branched polypropylenes

Cited by 87 publications

References 56 publications

A review of nonlinear oscillatory shear tests: Analysis and application of large amplitude oscillatory shear (LAOS)

A review of nonlinear oscillatory shear tests: Analysis and application of large amplitude oscillatory shear (LAOS)

A Comprehensive Review on Controlled Synthesis of Long‐Chain Branched Polyolefins: Part 3, Characterization of Long‐Chain Branched Polymers

The Influence of Heat Treatment on Uniaxial Elongational Flow Behavior of PS/SBS Blends

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