Dispersed polypropylene fibrils improve the foaming ability of a polyethylene matrix

Rizvi, Ali; Park, Chul

doi:10.1016/j.polymer.2014.06.014

Cited by 86 publications

(74 citation statements)

References 43 publications

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“…Also, elongational viscosity measurements have shown the induction of strain hardening as a result of improved interface in fibrillar networks. The appearance of secondary plateau and strain hardening due to the fibrillar morphology have been observed for the systems composed of PET, PTFE, PBT, PS, and PA6 .…”

Section: Introductionmentioning

confidence: 81%

Investigation of rheology and morphology to follow physical fibrillar network evolution through fiber spinning of PP/PA6 blend fiber

Hajiraissi

Jahani

Hallmann

2017

Polymer Engineering & Sci

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This work is aimed at investigating the influence of fibrillar morphology of deformed Polyamide 6 (PA6) droplets dispersed in Polypropylene (PP) matrix on the melt viscoelastic behavior of their blends. The blends of PP with various amounts of PA6 (1%, 6%, 10%, and 20%) were prepared by melt mixing in a co‐rotating twin screw extruder and fibrillated by fiber spinning process. Scanning Electron Microscopy revealed that the PA6 spherical droplets form fibrillar inclusions after fiber spinning. The steady and transient shear rheological responses of samples were evaluated in both linear and nonlinear ranges of deformation. Non‐terminal behavior of storage modulus at low frequency appeared as a typical characteristic of fibrillar morphology whose width and value depend on fibril growth. Storage modulus and complex viscosity of the blends containing PA6 fibrillated structure were remarkably enhanced compared to as‐extruded samples. The fibrillar‐induced elasticity of the fibers is a distinguishable behavior which was revealed by conducting transient stress and creep‐recovery measurements and upon appearing mature fibrils, elasticity of the polymer blend fibers increased significantly. POLYM. ENG. SCI., 58:1251–1260, 2018. © 2017 Society of Plastics Engineers

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Section: Introductionmentioning

confidence: 81%

Investigation of rheology and morphology to follow physical fibrillar network evolution through fiber spinning of PP/PA6 blend fiber

Hajiraissi

Jahani

Hallmann

2017

Polymer Engineering & Sci

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“…For a given PET content, the submicron diameter of the fibrillated-PET domains offers a larger surface-to-volume ratio in comparison with spherical-PET domains (which have diameters on the micrometer scale). Consequently, a larger area of contact between the matrix and the fibrillar domains is realized than with spherical domains thereby increasing the crystallization rate [24].…”

Section: Isothermal Crystallization Kineticsmentioning

confidence: 99%

Tuning viscoelastic and crystallization properties of polypropylene containing in-situ generated high aspect ratio polyethylene terephthalate fibrils

Rizvi

Park

Favis

2015

Polymer

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“…Influence of Fibril Diameter and Length on Linear Melt Viscoelastic Behavior : According to the observed linear melt viscoelastic responses of samples, it is obvious that upon transition from spherical shape to elongated structure the terminal trend of storage modulus in the low‐frequency region is replaced with non‐terminal behavior 28–30,39. This behavior appears as a widened secondary plateau in the low‐frequency region and the more the fibril elongates, the more the fibril penetrates into the matrix and consequently, frequency independency becomes broadened 13,31–34,36…”

Section: Resultsmentioning

confidence: 99%

“…In addition to traditional microscopic techniques which are used to study fibrils structurally, rheology has also represented itself as a powerful method to follow droplet deformation as the most important mechanism during processing. Mainly three test methods have been used to analyze the influence of fibrillation on melt viscoelastic properties of the blend systems: melt flow rate (MFR),25 extensional rheometry,26–28 and oscillatory rheometry 8,13,29–34. To the best of our collection, most of the works have concentrated on reporting the typical characteristics of fibrillar systems observed as a secondary plateau in a low‐frequency region, which is shared with nanocomposite polymers containing nano‐fillers35 and there is a lack of information about specific steps of fibrillation and its influence on elasticity of the blend system which is under control of fibril polymorphism.…”

Section: Introductionmentioning

confidence: 99%

An Insight into Phenomenology of Polytrimethylene Terephthalate Fibrillation

Hajiraissi

2020

Macro Materials & Eng

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The objective of this work is to analyze the effect of the processing temperature on fibrillation of the dispersed phase and to correlate melt viscoelastic responses to formed morphologies. A blend system of polypropylene (PP)/polytrimethylene terephthalate (PTT) with varying ratios (PP/PTT: 99/1, 94/6, 90/10, and 80/20) is prepared on a co‐rotating twin screw extruder, and then pelletized blend samples are fed into a laboratory mixing extruder to spin monofilaments at three different orifice temperatures of 180, 195, and 240 °C. As revealed by scanning electron microscopy, a nano‐fibrillar morphology forms after employing spinning. Rheological approach performed in the linear region shows a transition from terminal trend into non‐terminal trend in the low‐frequency region when the fibrillar morphology forms, the magnitude and width of which are reflective of the fibril growth. Transient stress measurements prove its capability to enable the blend system to show potentials of morphology development during dynamic tests. Startup of steady shear flow shows that after reaching the percolation concentration of dispersed phase, fibril–fibril coalescence leads to the formation of long fibrils whose contribution to the blend system increases the elasticity of the blend fibers.

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Dispersed polypropylene fibrils improve the foaming ability of a polyethylene matrix

Cited by 86 publications

References 43 publications

Investigation of rheology and morphology to follow physical fibrillar network evolution through fiber spinning of PP/PA6 blend fiber

Investigation of rheology and morphology to follow physical fibrillar network evolution through fiber spinning of PP/PA6 blend fiber

Tuning viscoelastic and crystallization properties of polypropylene containing in-situ generated high aspect ratio polyethylene terephthalate fibrils

An Insight into Phenomenology of Polytrimethylene Terephthalate Fibrillation

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