A comparative study of SiO2- and ZrO2-supported zirconocene/MAO catalysts on ethylene/1-olefin copolymerization

Pothirat, Tipawan; Jongsomjit, Bunjerd; Praserthdam, Piyasan

doi:10.1016/j.catcom.2007.12.005

Cited by 16 publications

(10 citation statements)

References 28 publications

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“…In addition, the effect of 1-olefin indicated that the activity of EO was higher than that of EH copolymerization. This result is consistent with the results reported by other researchers [9][10][11]. The result also explained that the chain length of the α-olefin has a little influence on the comonomer incorporation [12].…”

Section: Resultssupporting

confidence: 93%

Copolymerization of Ethylene/1-Olefin with Mesoporous Titania-Supported Zirconocene/MAO Catalyst

Amornlertpreecha¹,

Shiono²,

Jongsomjit

2012

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Different mesoporous titanias synthesized by hydrolysis and polycondensation reactions of tetrabutyl titanate with various hydrolysis ratios (H2O/Ti by mole) were employed as supports for zirconocene/MAO catalysts in ethylene/1-olefin copolymerization. The pure anatase phase of titania was detected by X-ray diffraction (XRD) and the morphology was seen by scanning electron microscopy (SEM). The titania obtained was then impregnated with methylaluminoxane (MAO). The amounts of [Al]MAO were measured by energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The copolymerization of ethylene/1-hexene (EH) and ethylene/1octene (EO) was performed using titania-supported zirconocene/MAO catalysts. Upon polymerization, it was found that the high surface area of titania apparently exhibited high polymerization activity due to large amounts of [Al]MAO present as seen by EDX and XPS. The obtained copolymer was further characterized by 13 C nuclear magnetic resonance (13 C NMR) and differential scanning calorimetry (DSC). It revealed that based on 13 C NMR, the random copolymer was obtained for both EH and EO systems. However, EH copolymer exhibited higher melting temperature (Tm) than EO copolymer indicating that the EH system had less comonomer incorporation.

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Section: Resultssupporting

confidence: 93%

Copolymerization of Ethylene/1-Olefin with Mesoporous Titania-Supported Zirconocene/MAO Catalyst

Amornlertpreecha¹,

Shiono²,

Jongsomjit

2012

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“…The degree of interaction between the support and the [Al] MAO can be determined by TGA . Our study of these systems led us to propose a support‐[Al] MAO interaction similar to those described by Pothirat et al This framework postulates that connections are formed between oxygen on the support and the Al of the co‐catalyst. Because different types of support‐materials have different surface properties, each may contain its own OAl bonding scheme with different bond energies and degrees of interaction.…”

Section: Resultssupporting

confidence: 60%

Characterization of MAO‐Modified Silicas for Ethylene Polymerization

Mortazavi

Ahmadjo

Santos

et al. 2013

J of Applied Polymer Sci

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A series of methylaluminoxane (MAO)-modified PQ and EP 12 silicas, calcined at 110, 250, and 450 C, were prepared.The resulting MAO-modified supports were characterized by a set of complementary techniques: Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), small angle X-ray scattering (SAXS), and thermal gravimetric analysis (TGA). The Al/Si ratios of the MAO-modified PQ and EP12 silicas were in the ranges of 0.19-0.27 wt % and 0.17-0.30 wt %, respectively. MAO-modified silicas were used in the polymerization of ethylene using an Et 2 IndZrCl 2 catalyst. The MAO-modified PQ silica showed higher activity in comparison to the MAO-modified EP12.

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“…2; the SiO 2 in all ash samples generated at 700 and 900 • C is amorphous. The assignment of the hump within 2Â = 15-30 • to amorphous silica has been made in previous studies [24][25][26][27]. The formation of crystalline SiO 2 through heating at 1100 • C would result in a decrease in porosity, thereby leading to more exposure of Cu to the TCLP leaching fluid and consequently greater copper leaching.…”

Section: Resultsmentioning

confidence: 90%