The Influence of Calcium‐Stearate‐Coated Calcium Carbonate and Talc on the Quiescent and Flow‐Induced Crystallization of Isotactic Poly(propylene)

D’Haese, Michelle; Goderis, Bart; Puyvelde, Peter Van

doi:10.1002/mame.201000351

Cited by 12 publications

(9 citation statements)

References 47 publications

(92 reference statements)

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“…Here the development of the storage modulus as a function of time at a certain temperature has been used as a measure for crystallisation and the results are generally in good agreement with other measurement techniques, such as DSC [34]. In Figure 14 the development of the storage modulus as a function of time is presented.…”

Section: Resultsmentioning

confidence: 56%

The Influence of Graft Length and Density on Dispersion, Crystallisation and Rheology of Poly(ε-caprolactone)/Silica Nanocomposites

et al. 2019

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Different techniques of grafting polymer chains to filler surfaces are often employed to compatibilise filler and polymer matrices. In this paper the influence of graft length and graft density on the state of dispersion, crystallisation and rheological properties of poly(ε-caprolactone) (PCL)/silica (SiO2) nanocomposites are reported. Grafted silica nanoparticles were prepared through polymerisation of PCL from the nanoparticle surface. Graft length was controlled by the reaction time, while the grafting density was controlled by the monomer-to-initiator ratio. Grafted nanoparticles were mixed with PCL of different molecular weights and the state of dispersion was assessed. Different matrix-to-graft molecular weight ratios resulted in different states of dispersion. Composites based on the higher molecular weight matrix exhibited small spherical agglomerates while the lower molecular weight matrix revealed more sheet-like microstructures. The state of dispersion was found to be relatively independent of graft length and density. Under quiescent conditions the grafts showed increased nucleation ability in the higher molecular weight PCL, while in the lower molecular weight matrix the effect was less pronounced. Rheological experiments showed an increase in viscosity with increased filler content, which was beneficial for the formation of oriented structures in shear-induced crystallisation.

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Section: Resultsmentioning

confidence: 56%

The Influence of Graft Length and Density on Dispersion, Crystallisation and Rheology of Poly(ε-caprolactone)/Silica Nanocomposites

et al. 2019

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“…From this figure, it can be seen that the effect of concentration on the nucleation efficiency already saturates at quite low concentrations of about 1 wt % (only 0.16 vol %). It has been reported previously that the effect of particles on nucleation saturates at (much) lower concentrations than those commonly used in commercial products (20−30 wt %), 20,56,57 however, the precise mechanism underlying this saturation with particle concentration is still unclear. This mechanism, though, is clearly not related to the ability of a polymer to nucleate onto a foreign surface: for the 500 nm zinc oxide saturation occurs at a nucleating efficiency of 6%, but this is not the maximum attainable nucleating efficiency for this polymer.…”

Section: ■ Materials and Methodsmentioning

confidence: 98%

On the Effect of Particle Size, Shape, Concentration, and Aggregation on the Flow-Induced Crystallization of Polymers

2013

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In this work, the combined effect of particles and flow on the crystallization of polymers has been investigated, using a rheo-optical approach. The effect of particle size, concentration, shape, and aggregation on the kinetics of flow-induced crystallization is investigated. It is shown that at high enough flow rates, flow will dominate the nucleation process, independent of the presence of particles, whatever their size, shape and concentration. Moreover, a framework will be presented to explain the additive effect of the presence of particles and flow on polymer crystallization. Finally, possible deviations from this additive rule (“synergetic effects”) will be discussed.

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“…The effect of flow on the kinetics of crystallization was studied previously . In particular, Coccorullo et al used optical microscopy to determine nucleation and growth rate of iPP under weak shear deformation (

\dot{γ}

= 0−0.3 s −1 ) using the Linkam shearing cell (CSS 450).…”

Section: Introductionmentioning

confidence: 99%

Quiescent crystallization of polypropylene: Experiments and modeling

Derakhshandeh

Mozaffari

Doufas

et al. 2014

J. Polym. Sci. Part B: Polym. Phys.

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The quiescent crystallization of several polypropylenes (PPs) was examined using Differential Scanning Calorimetry (DSC) and Polarized Optical Microscopy (POM). The halftimes of crystallization were obtained from the DSC thermographs employing the Avrami/Nakamura equation to fit and predict crystallization kinetics under isothermal and nonisothermal conditions. The induction times under nonisothermal conditions were estimated from isothermal crystallization data and used in conjunction with the Nakamura model in order to capture the crystallization behavior of the studied PPs. The Avrami/Nakamura model is found to fit and predict the nonisothermal crystallization data of the various PPs well over a range of cooling rates supporting its use in the simulation of polymer processes of industrial relevance. POM was used in line with parallel plate rheometry (Anton Paar, MCR 502) under no flow conditions to study the shape and growth rate of crystals of various PP resins at different temperatures or cooling rates. The growth rate of crystals is impeded exponentially with increase of temperature. The various PP resins of different molecular architecture have shown different nucleation and growth rate characteristics behavior under similar processing conditions.

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The Influence of Calcium‐Stearate‐Coated Calcium Carbonate and Talc on the Quiescent and Flow‐Induced Crystallization of Isotactic Poly(propylene)

Cited by 12 publications

References 47 publications

The Influence of Graft Length and Density on Dispersion, Crystallisation and Rheology of Poly(ε-caprolactone)/Silica Nanocomposites

The Influence of Graft Length and Density on Dispersion, Crystallisation and Rheology of Poly(ε-caprolactone)/Silica Nanocomposites

On the Effect of Particle Size, Shape, Concentration, and Aggregation on the Flow-Induced Crystallization of Polymers

Quiescent crystallization of polypropylene: Experiments and modeling

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