Reactor residence-time distribution effects on the multistage polymerization of olefins—III. Multi-layered products: impact polypropylene

Debling, Jon A.; Zacca, Jorge Jardim; Ray, W. Harmon

doi:10.1016/s0009-2509(97)00025-0

Cited by 47 publications

(27 citation statements)

References 24 publications

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“…It was previously reported in the literature that at high EPR contents (i.e., above 50% total weight), the copolymer phase becomes the continuous phase with PP fragments dispersed throughout. [5][6][7] This point coincides closely with the point where mass transfer resistance is encountered in the production of EPR particles. Further support of this idea comes from Debling,5 who noted that particles containing on the order of 70% EPR are observed to be hollow.…”

Section: Particle Morphologysupporting

confidence: 62%

Study of the kinetics, mass transfer, and particle morphology in the production of high‐impact polypropylene

Kittilsen

McKenna

2001

J of Applied Polymer Sci

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A sequence of experimental steps was perfected to produce high-impact modified polypropylene (PP), and to study the influence of particle morphology and rubber content on the reaction kinetics, especially in terms of mass transfer limitations. It was found that after a critical copolymer content at approximately 40% (with respect to total weight), it was impossible to obtain high reaction rates. This is thought to be the result of a fundamental change in particle morphology attributed to the presence of a soft EPR copolymer phase in the micropores.

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Section: Particle Morphologysupporting

confidence: 62%

Study of the kinetics, mass transfer, and particle morphology in the production of high‐impact polypropylene

Kittilsen

McKenna

2001

J of Applied Polymer Sci

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“…This leads to the so-called ''replication phenomenon'', whereby the size distribution of the catalyst particles is neatly replicated by the size distribution of the polymer particles exiting the reactor, as illustrated in [46][47][48][49][50]. This picture of particle fragmentation and growth has been captured in its most important details by the multigrain model [36,[51][52][53][54][55][56][57][58][59][60] which was originally developed to describe the crystalline structures of TiCl 3 and TiCl 4 /MgCl 2 Ziegler-Natta catalysts, but has also been used extensively to describe metallocene and late transition metals catalysts supported on inorganic carriers.…”

Section: Single Particle Models -Mass-and Heat-transfer Resistancesmentioning

confidence: 99%

“…(50) to the monomer concentration in the secondary particle at a given radial position and time if a partition coefficient, K MP , between the two phases is known.…”

Section: Primary Particle or Microparticlementioning

confidence: 99%

Coordination Polymerization

Soares¹,

Simon²

2005

Handbook of Polymer Reaction Engineering

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“…Among the ways to overcome the poor impact strength, the in-reactor blending of iPP with other polyolefins (especially ethylene-propylene rubber, EPR) by sequential multistage polymerization has proved to be the best method for the impact strength improvement of iPP. High-impact polypropylene (HiPP) in-reactor alloys have been widely applied in automobile parts, appliances, and other industrial applications due to their excellent mechanical properties and relatively low production cost [9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Controlled properties of high-impact polypropylene in-reactor alloys by tailoring chemical structure and morphology

et al. 2015

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The compositional heterogeneity, morphology and melting behavior of two commercial high-impact polypropylene (HiPP) in-reactor alloys were systematically investigated by the combined use of thermal fractionation, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Correlations between the mechanical properties and the molecular architectures and phase morphologies were discussed. The results show that the mechanical properties of the alloys are strongly influenced by the contents of ethylene-propylene rubber (EPR) and ethylene-propylene block copolymer (EPC), intrinsic viscosity ratios of EPR and the matrix, and the morphology in polypropylene in-reactor alloys. The EPC component acts as a bridge connecting the dispersed amorphous phase and crystalline polypropylene matrix. The advanced impact toughness of the HiPP samples can be interpreted as a consequence of their high EPR content and the good compatibility between the different components in the multiphase system. When the xylene soluble (XS) component was 20 wt% and an intrinsic viscosity ratios (λ) of xylene soluble component and xylene insoluble (XIS) component was1.6, the impact strength and flexural modulus of the HiPP samples were higher than 50 kJ/m 2 and 900 MPa, respectively.

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Reactor residence-time distribution effects on the multistage polymerization of olefins—III. Multi-layered products: impact polypropylene

Cited by 47 publications

References 24 publications

Study of the kinetics, mass transfer, and particle morphology in the production of high‐impact polypropylene

Study of the kinetics, mass transfer, and particle morphology in the production of high‐impact polypropylene

Coordination Polymerization

Controlled properties of high-impact polypropylene in-reactor alloys by tailoring chemical structure and morphology

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