Surface effect of the MgCl2 support in Ziegler–Natta catalyst for ethylene polymerization: A computational study

Xie, Kefeng; Xu, Shengyuan; Wei, He; Wang, Jie; Huang, Anping; Zhang, Yonghui

doi:10.1016/j.apsusc.2022.153002

Cited by 42 publications

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References 69 publications

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“…(2.8), 49 [(CH 3 ) 2 NH 2 ][Zn 1.5 (μ 3 -O) 0.5 (F-tzba) 1.25 (bpy) 0.25 (μ 2 -F) 0.5 ] (2.5), 50 ZJNU-17 (2.5), 51 etc. The gas adsorption selectivity performance of C 2 H 2 for CO 2 in 1 and 2 is attributed to the difference in the strength of the interaction between the framework and the small molecule gas, as well as the difference in steric hindrance.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…To study the gas adsorption selectivity of 1 and 2 at room temperature, the adsorption behavior of the MOFs for mixed component gases was calculated and fitted by ideal solution adsorption theory (IAST). By fitting the isotherm adsorption curves of C 2 H 2 and CO 2 mixtures (Figure S13), we found that when the C 2 H 2 :CO 2 molar ratio is 50:50 at 298 K, the calculated selectivities of 1 and 2 are 3.5 and 3.2, respectively (Figure a,b), which can be comparable to those of some MOFs under the same conditions, such as ZJU-30a (2.4), UPC-112 (2.76), Zn-MOF-74 (1.92), FJU-36 (2.8), [(CH 3 ) 2 NH 2 ][Zn 1.5 (μ 3 -O) 0.5 (F-tzba) 1.25 (bpy) 0.25 (μ 2 -F) 0.5 ] (2.5), ZJNU-17 (2.5), etc. The gas adsorption selectivity performance of C 2 H 2 for CO 2 in 1 and 2 is attributed to the difference in the strength of the interaction between the framework and the small molecule gas, as well as the difference in steric hindrance.…”

Section: Resultsmentioning

confidence: 99%

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Two Structurally Similar Co₅ Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C₂H₂/CO₂ Separation

Gao

Ding

et al. 2022

Inorg. Chem.

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To reasonably design and synthesize metal–organic frameworks (MOFs) with high stability and excellent adsorption/separation performance, the pore configuration and functional sites are very important. Here, we report two structurally similar cluster-based MOFs using a pyridine-modified low-symmetry ligand [H4L = 2,6-bis(2′,5′-dicarboxyphenyl)pyridine], [(NH2Me2)2][Co5(L)2(OCH3)2(μ3-OH)2·2DMF]·2DMF·2H2O (1) and [Co5(L)2(μ3-OH)2(H2O)2]·2H2O·4DMF (2). The structures of 1 and 2 are built from Co5 clusters, which have one-dimensional open channels, but their microporous environments are different due to the different ways in which ligands bind to the metals. Both MOFs have extremely high chemical stabilities over a wide pH range (2–12). The two MOFs have similar adsorption capacities of C2H2 (144.0 cm3 g–1 for 1 and 141.3 cm3 g–1 for 2), but 1 has a higher C2H2/CO2 selectivity of 3.5 under ambient conditions. The difference in gas adsorption and separation between the two MOFs has been compared by a breakthrough experiment and theoretical calculation, and the influence of the microporous environment on the gas adsorption and separation performance of MOFs has been further studied.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Two Structurally Similar Co₅ Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C₂H₂/CO₂ Separation

Gao

Ding

et al. 2022

Inorg. Chem.

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“…Since these bonds of the active species 2 are longer and have larger bond angles, the larger the space of the active center, the easier it is to promote olefin polymerization, which indicates that bimetallic Complex 2 has a lower activation barrier and higher catalytic activity. Therefore, introducing a p -phenylene bridged structure in Complex 2 provides a significant space effect, making the catalyst more active in metal centers in a stable state. ,− …”

Section: Methodsmentioning

confidence: 99%

Prominent Spatial Structure and Synergistic Linkage Effects in Bimetallic Titanium Olefin Polymerization Catalysts

Zhang

Cao

Guo

et al. 2022

Ind. Eng. Chem. Res.

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In this contribution, the binuclear Ti olefin polymerization catalyst 1,4-phenoxy{[Me 2 Si(C 5 H 4 ) 2 ]TiCl} 2 (Complex 2) was synthesized by the reaction of hydroquinone with [Me 2 Si(C 5 H 4 ) 2 ]TiCl 2 . Compared to mononuclear [Me 2 Si-(C 5 H 4 ) 2 ]TiCl 2 (Complex 1), due to the synergistic effect of bimetals, Complex 2 was thermally more stable and showed higher activity up to 1.36 × 10 6 g/(mol Ti h) for ethylene polymerization at 120 °C. Remarkably, adding the phenoxy group in front of the metal center gives the catalyst a denser coordination environment, and the β-H elimination reaction is slowed down, thereby increasing the molecular weight of the polymer. DFT calculations showed that the Ti−Cp distances in active species 2 were extended by 0.059 and 0.063 Å, respectively, compared to those in active species 1. This makes the space of the active center more spacious and easier to promote olefin polymerization. Consequently, the copolymer's 1-octene monomer incorporation rate reaches 16.21 mol %, with a fracture strain of 1140% and a stress recovery (SR) of 65%.

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“…In general, for TPU the phase separation of hard and soft blocks that governs the final morphology, mechanical and thermal properties [ 12 , 13 ]. The incompatibility between the blocks can be finetuned not only by changing the composition and ratio of soft and hard segments but also by variation of hydrogen bonding caused by addition of nanofillers or by use of specific thermal programs [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. Estimation of the hydrogen bonding density, for example by IR-spectroscopy, can be a good tool for the prediction of mechanical behavior of the materials.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Long-Time Storage on the Structure and Properties of Multi-Block Thermoplastic Polyurethanes Based on Poly(butylene adipate) Diol and Polycaprolactone Diol

et al. 2023

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A series of semi-crystalline multi-block thermoplastic polyurethanes (TPU), containing poly(butylene adipate) (PBA), polycaprolactone (PCL) and their equimolar mixture (PBA/PCL) as a soft segment was synthesized. The changes in the physical-mechanical and thermal properties of the materials observed in the course of a 36-month storage at room temperature were related to the corresponding structural evolution. The latter was monitored using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXS) and mechanical tests (tensile strength test). The effects of the composition of the soft segment on the phase separation and crystallization of the soft segment were analyzed in detail. It was found that the melting temperature of the crystalline phase increases with storage time, which is associated with hindering of the phase separation of the hard and soft segments of the TPU samples as it was detected by FTIR.

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Surface effect of the MgCl2 support in Ziegler–Natta catalyst for ethylene polymerization: A computational study

Cited by 42 publications

References 69 publications

Two Structurally Similar Co₅ Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C₂H₂/CO₂ Separation

Two Structurally Similar Co₅ Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C₂H₂/CO₂ Separation

Prominent Spatial Structure and Synergistic Linkage Effects in Bimetallic Titanium Olefin Polymerization Catalysts

The Influence of Long-Time Storage on the Structure and Properties of Multi-Block Thermoplastic Polyurethanes Based on Poly(butylene adipate) Diol and Polycaprolactone Diol

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Surface effect of the MgCl2 support in Ziegler–Natta catalyst for ethylene polymerization: A computational study

Cited by 42 publications

References 69 publications

Two Structurally Similar Co5 Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C2H2/CO2 Separation

Two Structurally Similar Co5 Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C2H2/CO2 Separation

Prominent Spatial Structure and Synergistic Linkage Effects in Bimetallic Titanium Olefin Polymerization Catalysts

The Influence of Long-Time Storage on the Structure and Properties of Multi-Block Thermoplastic Polyurethanes Based on Poly(butylene adipate) Diol and Polycaprolactone Diol

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Product

Resources

About

Two Structurally Similar Co₅ Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C₂H₂/CO₂ Separation

Two Structurally Similar Co₅ Cluster-Based Metal–Organic Frameworks Containing Open Metal Sites for Efficient C₂H₂/CO₂ Separation