Highly active and stereospecific catalyst based on β-TiCl3 for propylene polymerization

Costa, Marcos Heil; Silva, Ana L.S.S.; Coutinho, Fernanda M. B.; Maria, Luiz Cláudio de Santa; Pereira, Romeu A.

doi:10.1016/0032-3861(96)87267-3

Cited by 5 publications

(3 citation statements)

References 11 publications

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“…It is well known from the literature that β‐TiCl 3 forms fibrous structures which are brown, while the three other modifications ( α‐ , γ‐ , and δ‐TiCl 3 ) form a violet layer lattice structure with cubic or hexagonal close packaging. The trend toward more layered modifications (violet) with increasing amounts of EtAlCl 2 as described in the literature was also confirmed.…”

Section: Resultssupporting

confidence: 80%

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Effects of Alterations to Ziegler–Natta Catalysts on Kinetics and Comonomer (1‐Butene) Incorporation

Aigner

Averina

Garoff

et al. 2017

Macro Reaction Engineering

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system. Ziegler-Natta (ZN) catalysts generally dominate in PE and PP production, but they have their limitations when higher α-olefins are used for copolymerization. The disadvantages of ZN systems in this case are uneven and limited comonomer incorporation. The comonomer is incorporated randomly along the polymer chain, with a tendency to higher comonomer concentrations in the low-molecular weight fractions and less in the high molecular weight part. Further, ZN catalysts lead to broad molecular weight distributions (MWDs), which may be problematic with respect to the amount of extractable material.Higher-branched low molecular weight parts lead to a faster degradation which reduces the durability of the polymer material. Therefore, polyolefines with a homogeneous comonomer incorporation show beneficial properties concerning tensile strength, film transparency, and environmental stress cracking, which results in advantages for many applications, such as films and pipes. Metallocenes can tackle these requirements, as they can polymerize longer α-olefins (up to C26), yield narrow and homogeneous MWDs, and support comonomer incorporation of up to 20%. The demand for metallocene-based polyolefins, especially PE, is increasing significantly. The Various MgCl 2 -supported Ziegler-Natta (ZN) catalysts are synthesized with the intention to influence polymerization performance and 1-butene incorporation in an ethylene copolymer. Modifications are introduced during different steps in the synthesis process, namely support preparation, titanation, and catalyst workup. While multiple different effects are observed upon modification, heat treatment during titanation shows the greatest impact. Increasing the heat-treatment temperature increases polymerization activity. More importantly, the 1-butene distribution can be shifted toward a more homogeneous profile. The amount of 1-butene incorporated is similar to both for short-and for very long-chain molecules. This behavior has so far been known only from metallocene-based polyethylene and suggests that active sites are distributed more homogeneously in the ZN catalyst.

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Section: Resultssupporting

confidence: 80%

“…Published reports disagree on which of the four modifications, α‐ , β‐ , γ‐ , or δ‐TiCl 3, has the highest polymerization activity. In many cases, factors such as the catalyst recipe, pretreatment, polymerization conditions (comonomer, cocatalyst), and titanium oxidation state influence the activity to a greater extent …”

Section: Resultsmentioning

confidence: 99%

Effects of Alterations to Ziegler–Natta Catalysts on Kinetics and Comonomer (1‐Butene) Incorporation

Aigner

Averina

Garoff

et al. 2017

Macro Reaction Engineering

View full text Add to dashboard Cite

show abstract

“…TiCl 3 is well-established in industrial applications as one of the most important Ziegler–Natta catalysts for the synthesis of stereospecific olefins (polyethylene (PE) and polypropylene). − The main advantage of Ziegler–Natta pathways is its enormous flexibility, e.g., the polymer properties and the chain length can be adjusted by copolymerization with 1-alkenes, respectively, with hydrogen . As a consequence, it is possible to synthesize a broad range of polyolefins with different average molecular mass and density.…”

Section: Introductionmentioning

confidence: 99%

Layered α-TiCl₃: Microsheets on YSZ Substrates for Ethylene Polymerization with Enhanced Activity

et al. 2019

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The transition metal halide α-titanium(III) chloride (α-TiCl 3 ) is a layered two-dimensional compound and a well-established Ziegler−Natta catalyst for the polymerization of ethylene. A new synthesis technique is used to obtain thin sheets of α-TiCl 3 that show exceptional physical properties in contrast to their bulk counterparts, due to an enlarged surface-to-volume ratio. Chemical vapor transport (CVT) of α-titanium(III) chloride directly on substrates results in microsheets that exhibit an improved catalytic effect. For rational planning of synthesis conditions, thermodynamic simulations of occurring gas-phase equilibria were performed. Based on these calculation results, crystal growth was achieved by adding GaCl 3 via pure short term CVT in a temperature gradient of 700−600 K on yttrium-stabilized zirconia (YSZ) substrates. Phase pure, as-grown, single crystal sheets with high crystallinity and a thickness of around 4 μm were obtained. These thin sheets of α-TiCl 3 on YSZ substrates were implemented as catalysts for the ethylene polymerization reaction. A significant improvement of catalytic activity of 16% was achieved, probably due to an increased surface-to-volume ratio. As a highlight, the as-grown microsheets were exfoliated subsequently to a thickness lower than 200 nm and an even higher catalytic activity of up to 24% was confirmed experimentally due to delamination effects. This is the first time that an improved catalytic effect of α-TiCl 3 is observed as a result of downscaling from bulk to microsheets by CVT.

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Effect of di-n-butyl ether on the synthesis of Ziegler–Natta catalyst for propylene polymerization

Costa

Pereira

Coutinho

1999

European Polymer Journal

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Highly active and stereospecific catalyst based on β-TiCl3 for propylene polymerization

Cited by 5 publications

References 11 publications

Effects of Alterations to Ziegler–Natta Catalysts on Kinetics and Comonomer (1‐Butene) Incorporation

Effects of Alterations to Ziegler–Natta Catalysts on Kinetics and Comonomer (1‐Butene) Incorporation

Layered α-TiCl₃: Microsheets on YSZ Substrates for Ethylene Polymerization with Enhanced Activity

Effect of di-n-butyl ether on the synthesis of Ziegler–Natta catalyst for propylene polymerization

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Highly active and stereospecific catalyst based on β-TiCl3 for propylene polymerization

Cited by 5 publications

References 11 publications

Effects of Alterations to Ziegler–Natta Catalysts on Kinetics and Comonomer (1‐Butene) Incorporation

Effects of Alterations to Ziegler–Natta Catalysts on Kinetics and Comonomer (1‐Butene) Incorporation

Layered α-TiCl3: Microsheets on YSZ Substrates for Ethylene Polymerization with Enhanced Activity

Effect of di-n-butyl ether on the synthesis of Ziegler–Natta catalyst for propylene polymerization

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Layered α-TiCl₃: Microsheets on YSZ Substrates for Ethylene Polymerization with Enhanced Activity