Theoretical and Spectroscopic UV Study of the EtInd2ZrCl2/MAO, EtInd2ZrCl2/MAO-AlCl3 and EtInd2ZrCl2/MAO-Ethyl Benzoate Interaction

Ferreira, Marı́a Luján; Belelli, Patricia Gabriela; Damiani, Daniel Eduardo

doi:10.1002/1521-3935(20010201)202:4<495::aid-macp495>3.0.co;2-n

Cited by 18 publications

(10 citation statements)

References 25 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To interpret these observations, the interactions between the metallocene/MAO catalytic system and DEZ were examined by means of UV‐vis spectroscopy. This is a simple and effective methodology to investigate the active species of olefin coordination polymerization by a single site catalyst . As shown in Figure , the pure metallocene solution in toluene gave a maximal absorption wavelength at 430 nm.…”

Section: Resultsmentioning

confidence: 99%

Effect of Diethylzinc on the Activity of Ethylene Polymerization by Metallocene Catalyst

Wang

2015

Macro Reaction Engineering

View full text Add to dashboard Cite

Adding a suitable amount of diethylzinc as the third compound to a metallocene/MAO catalytic system for ethylene (co) polymerization gives rise to a sharp increase in activity. For ethylene homopolymerization, the activity is enhanced from 2.28 (Zn/Zr = 0) to 10.92 × 106 g/mol‐Zr/h (Zn/Zr = 100), and the activity for ethylene/1‐hexene copolymerization is enhanced from 7.68 (Zn/Zr = 0) to 16.20 × 106 g/mol‐Zr/h (Zn/Zr = 100). The activity decreases when the amount of diethylzinc is further increased. UV‐vis analysis shows that a mixed aluminoxane (MEAO) may be generated by the reaction of diethylzinc with MAO.

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of Diethylzinc on the Activity of Ethylene Polymerization by Metallocene Catalyst

Wang

2015

Macro Reaction Engineering

View full text Add to dashboard Cite

show abstract

“…The model of SMAO included 1 Al and 2 Si atoms. The Al atoms were saturated with O and the Si atoms with OH, according to previously published works 13–18…”

Section: Experimental Partmentioning

confidence: 99%

“…The zirconocenes were modeled with all their atoms, considering the structural information available, using the method developed by Ferreira et al13. This approach has produced manuscripts describing zirconocene adsorption on SiO 2 ,14 MAO adsorption on SiO 2 ,15 zirconocene reaction with MAO or SiO 2 16,17 and the presentation of a new model of active site for olefin polymerization 18,19…”

Section: Experimental Partmentioning

confidence: 99%

Ethylene and Propylene Polymerization Using In Situ Supported Me₂Si(Ind)₂ZrCl₂ Catalyst: Experimental and Theoretical Study

Franceschini¹,

Santos

Ferreira

et al. 2006

Macro Materials & Eng

View full text Add to dashboard Cite

Summary: Me2Si(Ind)2ZrCl2 was in situ immobilized onto SMAO and used for ethylene and propylene polymerization in the presence of TEA or TIBA as cocatalyst. The catalytic system Me2Si(Ind)2ZrCl2/SMAO exhibited different behavior depending on the amount and nature of the alkylaluminum employed and on the monomer type. The catalyst activity was nearly 0.4 kg polymer · g cat−1 · h−1 with both cocatalysts for propylene polymerization. Similar activities were observed for ethylene polymerization in the presence of TIBA. When ethylene was polymerized using TEA at an Al/Zr molar ratio of 250, the activity was 10 times higher. Polyethylenes made by in situ supported or homogeneous catalyst systems had practically the same melting point (Tm). On the other hand, poly(propylenes) made using in situ supported catalyst systems had a slightly lower Tm than poly(propylenes) made using homogeneous catalyst systems. The nature and amount of the alkylaluminum also influenced the molar mass. The poly(propylene) molar mass was higher when TIBA was the cocatalyst. The opposite behavior was observed for the polyethylenes. Concerning the alkylaluminum concentration, the molar mass of the polymers decreased as the amount of TEA increased. In the presence of TIBA, the polyethylene's molar mass was almost the same, independent of the alkylaluminum concentration, and the poly(propylene) molar mass increased with increasing amounts of cocatalyst. The deconvolution of the GPC curves showed 2 peaks for the homogeneous system and 3 peaks for the heterogeneous in situ supported system. The only exception was observed when TEA was used at an Al/Zr molar ratio of 500, where the best fit was obtained with 2 peaks. Based on the GPC deconvolution results and on the theoretical modeling, a proposal for the active site structure was made.Molar mass distribution deconvolution of polyethylene prepared with the system Me2Si(Ind)2ZrCl2/SMAO/TIBA with 500 mol/mol of alkylaluminum as cocatalyst.magnified imageMolar mass distribution deconvolution of polyethylene prepared with the system Me2Si(Ind)2ZrCl2/SMAO/TIBA with 500 mol/mol of alkylaluminum as cocatalyst.

show abstract

“…Some theories suggest that ionic pair of cationic catalyst and counter ion is completely separated from each other during monomer insertion and therefore the effect of counter ion on polymerization calculations is neglected [2,[8][9][10][11]. On the other hand, ionic pair model assumes that the catalytic active species can be stabilized by the strong electrostatic interaction with the counter ion and monomer inserts into the ionic pair of two ionic species [12][13][14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Ultra Accelerated Quantum Chemical Molecular Dynamics Study on Ethylene Polymerization Reaction Using CpSiH2NHTiCl2—Constrained Geometry Catalyst

et al. 2009

View full text Add to dashboard Cite

The ethylene polymerization process using constrained geometry catalyst CpSiH 2 -NH-TiCl 2 (CGC) was investigated by ultra accelerated quantum chemical molecular dynamics (UA-QCMD). We observed that the co catalyst MAO reacted with Ti CGC and forms ion pair within 85 fs. With the coordination of ethylene monomer the MAO-CGC ion pair dissociated and once the initial ethylene insertion has taken place, the further ethylene insertion occurring with a less energy barrier, is in good agreement with experimental findings.

show abstract

Theoretical and Spectroscopic UV Study of the EtInd2ZrCl2/MAO, EtInd2ZrCl2/MAO-AlCl3 and EtInd2ZrCl2/MAO-Ethyl Benzoate Interaction

Cited by 18 publications

References 25 publications

Effect of Diethylzinc on the Activity of Ethylene Polymerization by Metallocene Catalyst

Effect of Diethylzinc on the Activity of Ethylene Polymerization by Metallocene Catalyst

Ethylene and Propylene Polymerization Using In Situ Supported Me₂Si(Ind)₂ZrCl₂ Catalyst: Experimental and Theoretical Study

Ultra Accelerated Quantum Chemical Molecular Dynamics Study on Ethylene Polymerization Reaction Using CpSiH2NHTiCl2—Constrained Geometry Catalyst

Contact Info

Product

Resources

About

Theoretical and Spectroscopic UV Study of the EtInd2ZrCl2/MAO, EtInd2ZrCl2/MAO-AlCl3 and EtInd2ZrCl2/MAO-Ethyl Benzoate Interaction

Cited by 18 publications

References 25 publications

Effect of Diethylzinc on the Activity of Ethylene Polymerization by Metallocene Catalyst

Effect of Diethylzinc on the Activity of Ethylene Polymerization by Metallocene Catalyst

Ethylene and Propylene Polymerization Using In Situ Supported Me2Si(Ind)2ZrCl2 Catalyst: Experimental and Theoretical Study

Ultra Accelerated Quantum Chemical Molecular Dynamics Study on Ethylene Polymerization Reaction Using CpSiH2NHTiCl2—Constrained Geometry Catalyst

Contact Info

Product

Resources

About

Ethylene and Propylene Polymerization Using In Situ Supported Me₂Si(Ind)₂ZrCl₂ Catalyst: Experimental and Theoretical Study