Gas Phase Polymerization of α-Olefins with Ziegler — Natta and Metallocene Catalysts: a Comparison

Hungenberg, Klaus‐Dieter; Kerth, J.; Langhauser, Franz; Marczinke, B.; Schlund, Rüger

doi:10.1007/978-3-642-79136-9_20

Cited by 26 publications

(20 citation statements)

References 20 publications

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“…The measureable concentration of regioerrors contributed to this low melting point. [33][34][35]40,47 The low melting point in the context of Figures 12 and 13 suggested that addition of the m-iPP to a ZN-iPP matrix should lower the y (T). This is what is observed in Figure 2.…”

Section: Discussionmentioning

confidence: 98%

“…[33][34][35][36][37][38][39][40][41][42][43][44][45][46] The melting point of m-iPP is tunable, not only by tacticity (as in ZN-iPP), but also by the level of regiomisinser- tions. [33][34][35]40,47 Recent work demonstrated that m-iPP can expand the crystallinity-melting point property map of ZN-iPP to lower melting structures. 33 This implies a potential shift in the processing-property balance in BOPP applications relative to ZN-iPP.…”

Section: Introductionmentioning

confidence: 99%

“…However, m-iPP also exhibits a narrowed interchain tacticity and molecular weight distribution relative to ZN-iPP. [33][34][35]47,48 When used as a homopolymer, the narrow interchain tacticity distribution is expected to be a significant limitation of m-iPP in BOPP applications due to a narrowing of the temperature window for stretching. 49 This led to mixed catalyst strategies when using all metallocene BOPP formulations.…”

Section: Introductionmentioning

confidence: 99%

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Structure, processing, morphology, and property relationships of biaxially drawn Ziegler–Natta/metallocene isotactic polypropylene film

Phillips¹,

Nguyen²

2001

J of Applied Polymer Sci

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ABSTRACT:The structure, processing, morphology, and property relationships of biaxially drawn isotactic polypropylene (BOPP) film of mixed metallocene isotactic PP (m-iPP) and Ziegler-Natta iPP (ZN-iPP) homopolymer compositions are developed. The DSC and film drawing behavior show cocrystallization of the ZN-iPP and m-iPP components. The structure, processing, morphology, and property relations of ZN-iPP/ m-iPP blends are compared with ZN-iPP of varying isotacticities. The ZN-iPP/m-iPP blends exhibit reduced biaxial yield stress [ y (T)]. A fractional crystallinity model collapses the y (T) data into a common normalized form over a range of draw temperatures, ZN-iPP tacticities, and blend compositions. The simplified model is extended to define the interrelationships of yield activation and strain hardening behavior into regimes differentiated by characteristic draw stress (crystallinity) levels. Structureproperty models are developed to explain the effect of draw temperature and resinblend microstructure on the draw behavior, film stiffness, barrier, elongation, and synergies of the BOPP film processing-property balance.

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Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Structure, processing, morphology, and property relationships of biaxially drawn Ziegler–Natta/metallocene isotactic polypropylene film

Phillips¹,

Nguyen²

2001

J of Applied Polymer Sci

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“…In this way, the entire joint CL and CC distribution can be determined (Wild et a!. , 1982;Usami et a!., 1986;Wild, 1991 ;Soares , 1994;Hungenberg et a!., 1995;Takaoka et a!., 1995;Williams, 1996).…”

Section: Instantaneous Joint Chain Length and Composition Distributionmentioning

confidence: 98%

Simulating Joint Chain Length and Composition Fractions from Semi-Batch Ethylene Copolymerization Experiments

Shaw

McAuley

Bacon

1998

Polymer Reaction Engineering

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Linear low density polyethylenes produced using a-olefin comonomers and heterogeneous Ziegler-Natta catalysts have broad chain length (CL) and copolymer composition (CC) distributions. Multiple types of active sites on the catalyst are the cause of these broad and often multimodal distributions that influence both end-use and processing behaviour of the copolymer. Measurement of the joint CL and CC distribution can be accomplished by crossfractionating polyethylene by Temperature Rising Elution Fractionation (TREF) and Size Exclusion Chromatography (SEC). Using these techniques, copolymer can be separated into bins corresponding to specific CC and CL ranges. In this article, Stockmayer's (1945) bivariate distribution is used to develop a methodology for modelling the quantity of accumulated copolymer that corresponds to each specific bin of the joint CL and CC distribution. First, the instantaneous joint CL and CC distribution for polymer produced at each site type is integrated over specified finite ranges of composition and chain length. The end points of these ranges correspond to TREF fraction composition limits and selected chain lengths from SEC analyses. The instantaneous rate of polymer production from all site types in each of the bins is then calculated. The polymer accumulated in each bin over the course of a polymerization experiment is determined by numerically solving a set of ordinary differential equations. This methodology can be used to predict experimental TREF and SEC cross-fractionation results for copolymer produced dynamically in semi-batch laboratory reactors. The resulting predictions can then be used with experimental results to estimate parameters in kinetic models describing ethylene copolymerization with multiple active site catalysts.

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“…They exceed the rates of the gas-phase polymerization of propylene over industrial TMC. 13 Dependence of the selectivity of the process on the magnesium content at the step of eryochemical synthesis is given in Fig. 2.…”

mentioning

confidence: 99%

Cryosynthesis of catalysts for propylene oligomerization based on titanium tetrachloride and magnesium

et al. 1999

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A highly dispersed catalyst for oligo-and polymerization of propylene was synthesized by the interaction of TiCI 4 with magnesium in the cocondensates of their vapor with benzene and pentane. The catalyst contains MgCI 2 and organotitanium and organomagnesium cluster derivatives. The transformations of propylene and hex-l-ene over the catalyst.~ were studied. The direction of catalytic reactions and activity of the catalyst depend on the TiCl 4 : Mg molar ratio and the hydrocarbon used. Systems with an equimolar ratio of the reactants obtained in a benzene matrix exlu'bit the highest activity. Propylene oligomers containing a considerable fraction of unsaturated bonds are formed in the presence of the catalysts at room temperature and a pressure of 300 Tort.

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Gas Phase Polymerization of α-Olefins with Ziegler — Natta and Metallocene Catalysts: a Comparison

Cited by 26 publications

References 20 publications

Structure, processing, morphology, and property relationships of biaxially drawn Ziegler–Natta/metallocene isotactic polypropylene film

Structure, processing, morphology, and property relationships of biaxially drawn Ziegler–Natta/metallocene isotactic polypropylene film

Simulating Joint Chain Length and Composition Fractions from Semi-Batch Ethylene Copolymerization Experiments

Cryosynthesis of catalysts for propylene oligomerization based on titanium tetrachloride and magnesium

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