Effect of Different Aluminum Alkyls on the Metallocene/Methylaluminoxane Catalyzed Polymerization of Higher <i>α</i>‐Olefins and Styrene

Vasilenko, Irina V.; Kostjuk, Sergei V.; Kaputsky, Fyodor N.; Недорезова, П. М.; Aladyshev, A. M.

doi:10.1002/macp.200800024

Cited by 14 publications

(11 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Detailed kinetics of zirconium catalyzed ethylene polymerization provides key information for understanding the mechanism of these important industrial processes. As indicated by Busico et al [ 50 , 51 ], the chain propagation constant ( k p ) can be calculated using the “deceptively simple” rate law (Equations (2) and (3)) as follows: R p = k [M] R p = k p [C*][M] where [M] is monomer equilibrium concentration, [E] = 0.085 mol/L in toluene at 50 °C and 0.1 MPa was used for the calculation [ 26 , 52 ]. Since the instant polymerization rate at the time of TPCC quenching ( t p = 20 min) was not determined, the average R p value calculated from the polymer yield after 20 min polymerization and the catalyst amount has been used.…”

Section: Resultsmentioning

confidence: 89%

Kinetic and Thermal Study of Ethylene and Propylene Homo Polymerization Catalyzed by ansa-Zirconocene Activated with Alkylaluminum/Borate: Effects of Alkylaluminum on Polymerization Kinetics and Polymer Structure

et al. 2021

View full text Add to dashboard Cite

The kinetics of ethylene and propylene polymerization catalyzed by homogeneous metallocene were investigated using 2-thiophenecarbonyl chloride followed by quenched-flow methods. The studied metallocene catalysts are: rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 (Mt-I), rac-Et(Ind)2ZrCl2 (Mt-II) activated with ([Me2NPh][B(C6F5)4] (Borate-I), [Ph3C][B(C6F5)4] (Borate-II), and were co-catalyzed with different molar ratios of alkylaluminum such as triethylaluminium (TEA) and triisobutylaluminium (TIBA). The change in molecular weight, molecular weight distribution, microstructure and thermal properties of the synthesized polymer are discussed in detail. Interestingly, both Mt-I and Mt-II showed high activity in polyethylene with productivities between 3.17 × 106 g/molMt·h to 5.06 × 106 g/molMt·h, activities were very close to each other with 100% TIBA, but Mt-II/borate-II became more active when TEA was more than 50% in cocatalyst. Similarly, Polypropylene showed the highest activity of 11.07 106 g /molMt·h with Mt-I/Borate-I/TIBA. The effects of alkylaluminum on PE molecular weight were much more complicated; MWD curve changed from mono-modal in Mt-I/borate-I/TIBA to bimodal type when TIBA was replaced by different amounts of TEA. In PE, the active center fractions [C*]/[Zr] of Mt-I/borate were higher than that of Mt-II/borate and average chain propagation rate constant (kp) value slightly decreased with the increase of TEA/TIBA ratio, but the Mt-II/borate systems showed higher kp 1007 kp (L/mol·s). In PP, the Mt-I/borate presented much higher [C*]/[Zr] and kp value than the Mt-II. This work also extend to investigate the mechanistic features of zirconocenes catalyzed olefin polymerizations that addressed the largely unknown issues in zirconocenes in the distribution of the catalyst, between species involved in polymer chain growth and dormant state. In both metallocene systems, chain transfer with alkylaluminum is the dominant way of chain termination. To understand the mechanism of cocatalyst effects on PE Mw and (MWD), the unsaturated chain ends formed via β-H transfer have been investigated by 1H NMR analysis.

show abstract

Section: Resultsmentioning

confidence: 89%

Kinetic and Thermal Study of Ethylene and Propylene Homo Polymerization Catalyzed by ansa-Zirconocene Activated with Alkylaluminum/Borate: Effects of Alkylaluminum on Polymerization Kinetics and Polymer Structure

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The M w /M n invariably remained relatively broad throughout the reactions (M w /M n = 1.8-2.0). [69][70][71] The M n,NMR of the polymer sample (determined from the peak intensity ratio of the aromatic ring protons at δ 6.3-7.3 ppm to the initiating α-end protons at δ 1.0 ppm) was slightly larger than the GPC data. Fig.…”

Section: Molecular Weight and Chemical Structure Of Poly( P-mest) In Ilsmentioning

confidence: 83%

Cationic polymerization of p-methylstyrene in selected ionic liquids and polymerization mechanism

Zhang

Guo

et al. 2016

Polym. Chem.

View full text Add to dashboard Cite

Cationic polymerization of p-methylstyrene ( p-MeSt) in imidazolium-based [NTf 2−1 ] ionic liquids (ILs) was investigated. The effects of the anions, cations, and alkyl chain length of ILs on p-MeSt solubility and viscosity were comprehensively studied. The COSMO-RS method, which is a valuable tool for screening and selecting ILs, was also applied to identify the most suitable solvent for p-MeSt cationic polymerization.The results revealed that p-MeSt cationic polymerization proceeded in a milder exothermic manner in ILs than in a traditional organic solvent. Controlled polymerizations were achieved in [Bmim][NTf 2 ] with a CumOH/BF 3 OEt 2 initiating system at −25°C when 2,6-di-tert-butylpyridine was introduced. The cationic polymerization mechanism of p-MeSt in ILs was proposed on the basis of the results of density functional theory and the terminal structures of polymers. † Electronic supplementary information (ESI) available. See View Article Online a GPC trace was bimodal; other GPC traces were all unimodal. [p-MeSt] 0 = 1.88 mol L −1 , [TMPCl] 0 = [CumCl] 0 = [CumOH] 0 = [p-MeStCl] 0 = 7.43 mmol L −1 , [TiCl 4 ] 0 = [BF 3 OEt 2 ] 0 = [SnCl 4 ] 0 = 133.69 mmol L −1 , T = −25°C. The reaction time in ILs and CH 2 Cl 2 was 2 h. Polymer Chemistry PaperThis journal is

show abstract

“…In the utilization of metallocene catalyst to mediate α‐olefin polymerization, alkylaluminum has been reported to be an important factor that drastically affects the catalyst activity in the polymerization reaction and influences the molecular weight of the resulting olefin polymers . In the utilization of metallocene catalyst to mediate the SBS hydrogenation reaction, alkylaluminum compounds have been added as part of the catalyst composition, as reported in some literatures .…”

Section: Resultsmentioning

confidence: 99%

Hydrogenation of polystyrene-b -polybutadiene-b -polystyrene mediated by group (IV) metal metallocene complexes

Chiang

Tsai

2017

J. Polym. Sci. Part A: Polym. Chem.

View full text Add to dashboard Cite

Various group (IV) metal complexes, namely bis(cyclopentadienyl) titanium dichloride, bis(pentamethylcyclopentadienyl) titanium dichloride, cyclopentadienyl titanium trichloride, pentamethylcyclopentadienyl titanium trichloride, bis(cyclopentadienyl) zirconium dichloride, and bis(cyclopentadienyl) hafnium dichloride, were used as the catalysts for mediating styrene–butadiene–styrene hydrogenation. The catalytic efficiency of these catalysts was examined. The results show that catalyst activity strongly depends on the chemical structure of the metallocene complex. We also found that trialkylaluminum has a significant influence on the hydrogenation activity and thermal stability of metallocene catalysts. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2141–2149

show abstract

Effect of Different Aluminum Alkyls on the Metallocene/Methylaluminoxane Catalyzed Polymerization of Higher α‐Olefins and Styrene

Cited by 14 publications

References 69 publications

Kinetic and Thermal Study of Ethylene and Propylene Homo Polymerization Catalyzed by ansa-Zirconocene Activated with Alkylaluminum/Borate: Effects of Alkylaluminum on Polymerization Kinetics and Polymer Structure

Kinetic and Thermal Study of Ethylene and Propylene Homo Polymerization Catalyzed by ansa-Zirconocene Activated with Alkylaluminum/Borate: Effects of Alkylaluminum on Polymerization Kinetics and Polymer Structure

Cationic polymerization of p-methylstyrene in selected ionic liquids and polymerization mechanism

Hydrogenation of polystyrene-b -polybutadiene-b -polystyrene mediated by group (IV) metal metallocene complexes

Contact Info

Product

Resources

About