Modelling flow induced crystallization of IPP: Multiple crystal phases and morphologies

Grosso, Giovanna; Troisi, EM Enrico; Peters, Gwm Gerrit; Anderson, Patrick Patrick

doi:10.1016/j.polymer.2019.121806

Cited by 22 publications

(43 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Isotactic polypropylene (iPP) is selected to exemplify the experimental method, as it is one of the best characterized polymers in terms of crystal structure and morphology. [ 15 ] Two homopolymer grades with weight average molar mass of 130 kg/mol (iPP‐1) and 365 kg/mol (iPP‐2) are kindly provided by Borealis Polyolefine GmbH (Linz, Austria). Both materials have a high isotacticity and a polydispersity index of 5.5.…”

Section: Methodsmentioning

confidence: 99%

Polarization modulated infrared spectroscopy: A pragmatic tool for polymer science and engineering

Looijmans

Carmeli

Puškar

et al. 2020

Polymer Crystallization

Self Cite

View full text Add to dashboard Cite

In the area of polymer crystallization, the most widely used techniques to quantify structure, morphology and molecular orientation are fundamentally based on light or X-ray scattering and absorption. In particular, synchrotron X-rays are used for detailed studies on the semicrystalline structure in polymeric materials. The technical requirements for such techniques, especially when high spatial resolution is essential, make the application of X-ray diffraction not straightforward. Direct information on the chain orientation in different semicrystalline morphologies requires rather complex sampling and analysis procedures. Surprisingly, a simple yet versatile technique based on infrared spectroscopy is hardly applied in the field of polymer crystallization. By modulating the polarization of the incident light, local anisotropy can be studied in real time on a submolecular length scale. In this article, we provide the relevant details of the polarization modulated infrared microspectroscopy technique for the study of semicrystalline materials from an engineering perspective. We demonstrate the essence of the method using as model systems spherulitic and transcrystalline morphologies and present its applicability to polymer/fiber composite technology and the study of injection-molded parts. The results provided in the present work serve to illustrate the applicability of this informative technique in the field of semicrystalline polymer science.

show abstract

Section: Methodsmentioning

confidence: 99%

Polarization modulated infrared spectroscopy: A pragmatic tool for polymer science and engineering

Looijmans

Carmeli

Puškar

et al. 2020

Polymer Crystallization

Self Cite

View full text Add to dashboard Cite

show abstract

“…The material used in this study is an iPP homopolymer (Borealis HD601CF, M w = 365 kg/mol, and M n = 68 kg/mol), which is characterized and examined in other studies. 21,24,26,31 The material rheology is fitted with the XPP constitutive model. Note that two different sets of XPP parameters are reported in literature.…”

Section: Modelingmentioning

confidence: 99%

“…The growth rate of the other two morphologies is always equal to the growth rate in quiescent conditions. 26 After flow, this effect relaxes due to relaxation of the chains towards their equilibrium conformation. Grosso et al 26 introduce a direct relation between the α-parent growth rate and the molecular conformation.…”

Section: Flow-induced Nucleation and Crystallizationmentioning

confidence: 99%

“…26 After flow, this effect relaxes due to relaxation of the chains towards their equilibrium conformation. Grosso et al 26 introduce a direct relation between the α-parent growth rate and the molecular conformation. The expression for the growth rate of α-parents is given by 26 : However, because the growth of daughter crystals only becomes noticeable after relaxation of the conformation, the growth rate for α-daughters equals the quiescent growth rate:…”

Section: Flow-induced Nucleation and Crystallizationmentioning

confidence: 99%

“…It shows good agreement with experimental data for crystallization over a very wide range of shear rates, pressures and temperatures. 24,25 Grosso et al 26 extended this model by using molecular considerations for setting the stretch relaxation times in the viscoelastic constitutive equation and the improved model can predict the formation of local complex structures of iPP in slit flows. 26 The continuum model of Grosso et al 26 has been implemented in an in-house developed finite element package (TFEM) and will be used in this study after generalization of the flow type to include extension.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A numerical study of extensional flow‐induced crystallization in filament stretching rheometry

Berlo

Cardinaels

Peters

et al. 2020

Polymer Crystallization

Self Cite

View full text Add to dashboard Cite

A finite element model is presented to describe the flow, resulting stresses and crystallization in a filament stretching extensional rheometer (FiSER). This model incorporates nonlinear viscoelasticity, nonisothermal processes due to heat release originating from crystallization and viscous dissipation as well as the effect of crystallization on the rheological behavior. To apply a uniaxial extension with constant extension rate, the FiSER plate speed is continuously adjusted via a radius-based controller. The onset of crystallization during filament stretching is investigated in detail. Even before crystallization starts, the rheology of the material can change due to the effects of flow-induced nucleation on the relaxation times. Both nucleation and structure formation are found to be strongly dependent on temperature, strain rate and sample aspect ratio. The latter dependence is caused by a clear distribution of crystallinity over the radius of the filament, which is a result of the nonhomogeneous flow history in the FiSER. Therefore, this numerical model opens the possibility to a priori determine sample geometries resulting in a homogeneous crystallinity or to account for the nonhomogeneity.

show abstract

Crystallization Behavior of Polypropylene and Its Blends and Composites

Mileva

Tranchida

Carmeli

et al. 2023

Polymer Crystallization

View full text Add to dashboard Cite

Modelling flow induced crystallization of IPP: Multiple crystal phases and morphologies

Cited by 22 publications

References 55 publications

Polarization modulated infrared spectroscopy: A pragmatic tool for polymer science and engineering

Polarization modulated infrared spectroscopy: A pragmatic tool for polymer science and engineering

A numerical study of extensional flow‐induced crystallization in filament stretching rheometry

Crystallization Behavior of Polypropylene and Its Blends and Composites

Contact Info

Product

Resources

About