Probing into Effects of Support Pre-Treatment on the Polymerization Behavior and Morphology Development of Mg(OEt)2-Based Ziegler–Natta Catalysts

Jandaghian, Mohammad Hossein; Maddah, Yasaman; Sepahi, Abdolhannan; Rashedi, Reza; Nikzinat, Ehsan; Masoori, Maryam

doi:10.1007/s10562-021-03715-4

Cited by 12 publications

(17 citation statements)

References 36 publications

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“…As can be seen, the main peaks of magnesium ethoxide support have vanished and been replaced with peaks at around 16, 20, 22, 25, 29, 30, 32, 33, 41, 43, 48, 52, 60, 63, and 68 in cat 1. The peaks in the catalyst are in perfect agreement with the previously published reports dealing with ZNC made by magnesium ethoxide supports. , In other words, it has been proved that magnesium ethoxide can be changed to magnesium chloride using TiCl 4 , EASC, and other chlorine-donating materials. − …”

Section: Resultssupporting

confidence: 87%

“…At first glance, industrially favorable ZNCs usually consist of magnesium chloride and TiCl 4 . While different types of donors, promotors, and so forth are frequently added to the base formulation, MgCl 2 and TiCl 4 can be considered the backbone of all ZNCs’ recipes. ,− In addition, MgCl 2 can be used as a starting material or produced in situ during ZNC synthetic approaches. − The second choice is strongly preferable, especially when a morphology-less catalyst is targeted. Most slurry-based polymerization technologies use Mg(OEt) 2 -based ZNCs to produce their products due to their low price and ease of handling. − …”

Section: Introductionmentioning

confidence: 99%

“…The chlorinating agent can be TiCl 4 or chlorinated alkylaluminium cocatalysts (CACs) such as ethylaluminum sesquichloride (EASC), ethylaluminum dichloride (DEAC), and diethylaluminum chloride (DEAC). ,− Unfortunately, chlorination of Mg(OEt) 2 with TiCl 4 decreases the performance of ZNCs in terms of activity and hydrogen response due to the formation of titanium islands. Because of this, the catalysts are not perfect options for producing highly effective polyethylene grades such as PE100 (a bimodal polyethylene grade used in the production of polyethylene pipes for the transportation of water and gases). , …”

Section: Introductionmentioning

confidence: 99%

“…Because of this, the catalysts are not perfect options for producing highly effective polyethylene grades such as PE100 (a bimodal polyethylene grade used in the production of polyethylene pipes for the transportation of water and gases). 15,16 On the other hand, chlorination of Mg(OEt) 2 using CACs is very challenging. CACs are very dangerous to use in petrochemical industries not only from the handling and transportation points of view but also because of their corrosion risks.…”

Section: Introductionmentioning

confidence: 99%

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Chlorination of Mg(OEt)₂ with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Jandaghian

Maddah

Sepahi³

et al. 2022

Ind. Eng. Chem. Res.

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Due to the many risks of using chlorinated alkylaluminum cocatalysts (CACs), reducing or omitting their amount in methods used for synthesizing Ziegler–Natta catalysts (ZNCs) has always been a dream of polymer chemists. CACs play a crucial role in the chlorination of Mg(OR)2 supports, which are the most industrially favorable precursors in ZNCs’ recipes. In this article, using a systematic investigation, an initiative approach has been suggested to chlorinate the supports using halocarbons and chlorine-free alkylaluminum cocatalysts (CFACs). It was evidenced that the successive addition of a CFAC and a halocarbon to a suspension of Mg(OR)2 is a reliable method for chlorine atom exchange between the halocarbon and Mg(OR)2. Doing so, a highly active ZNC was produced and characterized mainly by inductively coupled plasma, X-ray diffraction, and X-ray photoelectron spectroscopy techniques. In the next step, the catalyst’s performance in monomodal and bimodal copolymerization reactions of ethylene and 1-butene was investigated, and the produced copolymers were fully characterized. The characterizations were carried out using numerous techniques such as rheometric mechanical spectroscopy (RMS), self-nucleation and annealing, differential scanning calorimetry, mechanical tests, and so forth, and their results were compared with a famous ZNC whose support was chlorinated with a CAC. Finally, a possible mechanistic pathway for the reaction between Mg(OR)2 and halocarbons using CFACs as a chlorine transporter was described. All in all, it was revealed that the new approach could be relied upon as a promising way to chlorinate Mg(OR)2 supports without using dangerous and corrosive CACs. The produced copolymers using the new formulation had the same physical and mechanical properties as those made by industrial counterparts.

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Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Chlorination of Mg(OEt)₂ with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Jandaghian

Maddah

Sepahi³

et al. 2022

Ind. Eng. Chem. Res.

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“…As a general method, [36][37][38][39][40] all equipment was washed twice by distilled water and dried at 135 C overnight. Before use, all of them were treated with a 25 wt% solution of triethylaluminium (TEA) in hexane and purged with dry nitrogen for several hours.…”

Section: General Considerationmentioning

confidence: 99%

Effects of polymerization parameters on the slow crack growth resistance and rheological properties of bimodal polyethylene resins

Jandaghian

Maddah

Sepahi³

et al. 2021

J of Applied Polymer Sci

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In this paper, using a comprehensive study, we have investigated the effect of various polymerization parameters during the synthesis of bimodal polyethylene resins on their rheological and mechanical properties. Bimodal polyethylene resins were synthesized in two subsequent stages in a lab-scale reactor by manipulating a set of parameters such as C 2 /H 2 ratios in the first and second stages, the split value, and the comonomer type. The results showed that the comonomer type and C 2 /H 2 ratio of the second stage of the polymerization are the most critical parameters that control the final resins' slow crack growth resistance properties. On the other hand, the shear-thinning behavior of the resins is mainly controlled by the first-stage polymers. Although the C 2 /H 2 ratio of the first stage results in a moderate effect on the rheological properties of the final resins, its split value governs the flow characteristics of the final molten polymers under high shear rates.

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Chemical dealcoholation of MgCl₂·EtOH adduct by Al compounds and its effect on the performance of Ziegler–Natta catalysts

Bazvand,

Bahri‐Laleh,

Abedini

et al. 2023

Applied Organom Chemis

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MgCl2·nEtOH adducts play a major role in the industrial production of polyethylenes. Their chemical dealcoholation, usually accomplished during the catalyst synthesis step, has had a pronounced impact on the microstructure of the final Ziegler–Natta pre‐catalysts and the properties of the resulting polymers. Due to the industrial and academic importance of this issue, different aluminum‐based compounds including triethylaluminum (TEAL), triisobutylaluminum (TIBA), and ethylaluminumdichloride (EADC) were used in this research in the chemical dealcoholation of a MgCl2·1.5EtOH adduct, to provide the target catalysts. According to the analytical results, the catalysts synthesized using aluminum compounds (especially TEAL and EADC) generally had a more fractured structure, a smaller particle size and a vast surface area. Aluminum precursors bind to the catalyst structure together with TiCl4, which is manifested from their higher adsorption energies obtained by DFT calculations, and the presence of Al atom in the elemental analysis. Varying the chemical structure and physical properties of the catalysts, established using Al compounds, caused significant variation in the ethylene polymerization kinetic curves, their related rate constants, and the flow characteristic of the final polymers. The overall results outstandingly affirm that by appropriate choice of the Lewis acid compound, during the chemical dealcoholation of the adduct, various Ziegler–Natta catalysts can be achieved for different polyethylene grades.

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Probing into Effects of Support Pre-Treatment on the Polymerization Behavior and Morphology Development of Mg(OEt)2-Based Ziegler–Natta Catalysts

Cited by 12 publications

References 36 publications

Chlorination of Mg(OEt)₂ with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Chlorination of Mg(OEt)₂ with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Effects of polymerization parameters on the slow crack growth resistance and rheological properties of bimodal polyethylene resins

Chemical dealcoholation of MgCl₂·EtOH adduct by Al compounds and its effect on the performance of Ziegler–Natta catalysts

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Probing into Effects of Support Pre-Treatment on the Polymerization Behavior and Morphology Development of Mg(OEt)2-Based Ziegler–Natta Catalysts

Cited by 12 publications

References 36 publications

Chlorination of Mg(OEt)2 with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Chlorination of Mg(OEt)2 with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Effects of polymerization parameters on the slow crack growth resistance and rheological properties of bimodal polyethylene resins

Chemical dealcoholation of MgCl2·EtOH adduct by Al compounds and its effect on the performance of Ziegler–Natta catalysts

Contact Info

Product

Resources

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Chlorination of Mg(OEt)₂ with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Chlorination of Mg(OEt)₂ with Halocarbons: A Promising Approach for Eliminating Chlorine-Containing Activators from Ziegler–Nattas’ Recipes

Chemical dealcoholation of MgCl₂·EtOH adduct by Al compounds and its effect on the performance of Ziegler–Natta catalysts