Effect of rheological and physical properties on mitigation of melt fracture instability during extrusion of polymer melts through a radial flow die

Ketata, Moez; Ayadi, Ahmed; Elkissi, Nadia; Bradaï, Chedly

doi:10.1007/s00397-017-0995-2

Cited by 10 publications

(3 citation statements)

References 24 publications

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“…The fast dynamics of the hydrogen-bonding interaction was also seen in the low bond lifetimes of the samples ranging between 0.1 and 3.5 s, except for PDMS-25-MCU0.8-IU0.2 and PDMS-25-MCU1.0 showing supramolecular bond lifetimes of around 20−30 s (see Figure 3d). For comparison, the relaxation time of linear, high molecular weight PDMS with a weight-averaged molecular weight between 308000 and 500000 g mol −1 was determined to range between 0.013 and 0.020 s. 56 For all polymers of the PDMS-25-MPU series, the observed supramolecular bond lifetime was lower than for the elastomers of the PDMS-25-MCU series, although the hydrogen-bonding interaction between MPU units is expected to be stronger than between MCU units (see Figure 3d). This observation is matching with the trends within the Young's moduli (see Figure 2b) and is probably related to the higher molecular weight of the polymers of the PDMS-25-MCU series and therefore to a slightly higher absolute amount of incorporated hydrogen-bonding moieties.…”

Section: ■ Introductionmentioning

confidence: 99%

Tuning the Self-Healing Response of Poly(dimethylsiloxane)-Based Elastomers

Döhler

Kang

Cooper

et al. 2020

ACS Appl. Polym. Mater.

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We present a comprehensive investigation of mechanical properties of supramolecular polymer networks with rationally developed multistrength hydrogen-bonding interactions. Self-healing poly(dimethylsiloxane) (PDMS)-based elastomers with varying elasticity, fracture toughness, and the ability to dissipate strain energy through the reversible breakage and re-formation of the supramolecular interactions were obtained. By changing the ratio between isophorone diisocyanate (IU), 4,4′-methylenebis(cyclohexyl isocyanate) (MCU), and 4,4′-methylenebis(phenyl isocyanate) (MPU) and by varying the molecular weight of the PDMS precursor, we obtained a library of poly(urea)s to study the interplay of mechanical performance and self-healability. The Young's moduli of the presented materials ranged between 0.4 and 13 MPa and increased with decreasing molecular weight of the PDMS precursor and increasing content of MCU or MPU units related to the formation of stronger hydrogen-bonding interactions. By exchanging MPU against MCU units, we achieved an optimum balance between mechanical properties and self-healing performance, and by the additional reduction of the molecular weight of the precursor polymer, a minimum recovery of 80% in stress within 12 h at room temperature was observed. Selected poly(urea)s could be processed via 3D printing by the conventional extrusion method, obtaining dimensionally stable and freestanding objects.

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Section: ■ Introductionmentioning

confidence: 99%

Tuning the Self-Healing Response of Poly(dimethylsiloxane)-Based Elastomers

Döhler

Kang

Cooper

et al. 2020

ACS Appl. Polym. Mater.

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“…It should be noted that PDMS oils are known to be shear thinning at high strain rates [19]. Data for similar oils at strain rates approaching those relevant to spall experiments seem to indicate that the effective difference in viscosity between the two oils in the experiments is likely less than the factor of twenty exhibited at low strain rates [19,20]. The silicone oils: PSF-50CST and PSF-1000CST, were purchased from Clearco Products Co..…”

Section: -2mentioning

confidence: 99%

Dynamic tensile strength of silicone oils

Huneault

Kamil

Higgins

et al. 2018

AIP Conference Proceedings

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Abstract. The spall strength of polydimethylsiloxane silicone oils has been studied using the planar impact of thin flyers to generate large transient negative pressures near the free surface of target samples. The liquids were contained within sealed capsules in which a 4-µm-thick aluminized Mylar diaphragm formed a free surface at the back of the sample. The liquid targets were impacted by PMMA flyers at velocities ranging from 130 to 700 m/s using a 64-mm-bore gas-gun, thus allowing for large variations in the strain rate and incident shock pressure. The peak tension in the liquid was determined by monitoring the free surface velocity using a photonic Doppler velocimetry (PDV) system. The paper focuses on the study of a system of silicone oils having vastly different viscosities (5 cSt to 1000 cSt), but otherwise similar liquid properties. The effect of viscosity on spall strength is compared to previously published data and models.

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“…The manufacture of the plastic pipe is usually performed by the extrusion forming method of the polymer melt [1]. At the same time, the extrusion forming of the plastic pipe is usually achieved by the aid of the metal die with a certain of cross-shape.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on the effect of the die compression angle on extrusion forming of plastic pipe

2018

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Abstract. The effect of compression angle of die on the extrusion forming of plastic pipe was numerically studied by using the finite element method. Based on the geometric models of plastic pipes with four different compression angles, the extrudate swell results of plastic pipe under the different compression angles are numerically simulated. Numerical results show the extrudate swell phenomenon for the little compression angles are larger than that of the large compression angles. To eliminate the extrudate swell effect and keep the wear-resistant strength of the plastic pipe, the gas-assisted extrusion method was used in this paper. The numerical results fully show that the shear stress of melt was greatly eliminated and the high pressure was still maintained by using the gas-assisted method.

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Effect of rheological and physical properties on mitigation of melt fracture instability during extrusion of polymer melts through a radial flow die

Cited by 10 publications

References 24 publications

Tuning the Self-Healing Response of Poly(dimethylsiloxane)-Based Elastomers

Tuning the Self-Healing Response of Poly(dimethylsiloxane)-Based Elastomers

Dynamic tensile strength of silicone oils

Numerical study on the effect of the die compression angle on extrusion forming of plastic pipe

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