Determination of Mg, Ti and Cl in Ziegler-Natta catalysts by WDXRF

Bichinho, Kátia M.; Pires, Gilvan Pozzobon; Santos, João Henrique Zimnoch dos; Forte, Maria Madalena de Camargo; Wolf, Carlos Rodolfo

doi:10.1016/j.aca.2004.02.052

Cited by 13 publications

(6 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Titanocene dichloride, TiCl 4 , TiCl 3 , Ti(OR) 4 are active components in Ziegler-Natta catalyst for ␣-olefins polymerization and copolymerization [14][15][16]. Since TiCl 4 and Ti(OR) 4 are active catalysts for the transesterification of DMC and phenol, we thought that titanocene dichloride would also be an active catalyst in this reaction.…”

Section: Introductionmentioning

confidence: 98%

Cp2TiCl2 used as a catalyst for the transesterification between dimethyl carbonate and phenol to diphenyl carbonate

Niu

Yao

Wang

et al. 2005

Journal of Molecular Catalysis A: Chemical

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 98%

Cp2TiCl2 used as a catalyst for the transesterification between dimethyl carbonate and phenol to diphenyl carbonate

Niu

Yao

Wang

et al. 2005

Journal of Molecular Catalysis A: Chemical

View full text Add to dashboard Cite

“…The efficiency of this sample-preparation procedure is also in accordance with previous work, which reported that it used H2SO4 and heating to decompose commercial supported Ziegler-Natta catalysts for the determination of Ti and Mg using molecular absorption spectrometry. 14 It is supposed that the best metal recovery is due to the complete dissolution of V and Ti compounds by H2SO4. However, according to Table 2, there is no significant differences (P < 0.05) between procedures (1), (2) and (3); all three are recommended.…”

Section: Resultsmentioning

confidence: 99%

“…Particularly in the case of the Ziegler-Natta catalyst, one can mention metal content determination by X-ray fluorescence spectrometry (XRF), 13,14 X-ray photoelectron spectroscopy (XPS), [12][13][14][15] and Rutherford backscattering spectrometry (RBS). 16,17 Indeed, in the case of XPS and RBS, which are non-relative measurement techniques, calibration may not be necessary, and the results are expressed as atomic ratios.…”

Section: Introductionmentioning

confidence: 99%

Determination of Titanium and Vanadium in Ziegler-Natta Catalysts by Inductively Coupled Plasma Atomic Emission Spectrometry

et al. 2006

View full text Add to dashboard Cite

IntroductionZiegler-Natta catalysts are largely employed in industrial processes for the polymerization of α-olefins in order to produce materials, such as polyethylenes and polypropylenes. The main constituents of such catalysts are Ti and V, which are responsible for the catalytic activity, as a result of the immobilization of compounds, such as TiCl4 or VCl3, onto MgCl2 or SiO2 supports. 1 Catalyst properties and metal content are dependent on some experimental parameters, such as the order of catalyst addition to the support, the grafting time and temperature, the molar ratio among the catalyst and the cocatalyst (aluminum compounds, such as tributylaluminum). These parameters may affect the catalyst performance in the polymerization reaction as well as the properties of the attained polymers. Therefore, the catalyst metal content is an important parameter for evaluating the catalyst performance in terms of the activity, which is defined as the capacity of the catalyst to convert the feedstock into products. The activity is expressed as the ratio of the attained product by the mass of the catalyst, which is expressed as moles of metal. The determination of the metal content in catalysts can be carried out by various techniques, 2 but and in the case of Ziegler-Natta (ZN) catalysts, Ti and V are usually determined by molecular absorption spectrometry after reactions with H2O2 and H2SO4 and measurements at 410 nm and 450 nm, respectively.3-8 The major drawbacks of this technique are a low sampling throughput and high sample handling. In some studies, Ti or V was also determined by flame atomic absorption spectrometry (FAAS) 9-11 and inductively coupled plasma atomic emission spectrometry (ICP OES). 12 In the case of FAAS, the limit of detection (LOD) is not very good, since V and Ti may form compounds that are not completely destroyed in the flame, while in the case of ICP OES, the persistence of such compounds would be very unlikely due to the plasma temperature. However, despite the fact that ICP OES seems to be an appropriate technique, it has not usually been employed in ZN catalysts analysis.It is claimed that the major drawbacks of the above-mentioned techniques are the need for metal extraction from the bulk of the sample matrix, or sample decomposition with an acidic solution (acid digestion) prior to the analyte measurement. These procedures may be tedious, time-consuming and engender some systematic errors due to poor analyte extraction efficiency and solubility. It is expected that such problems may be overcome by using direct analysis techniques, which allow the analysis of solid samples without any analyte extraction or decomposition.Many techniques can provide direct metal determination in catalysts, differing in the measurement principle. Particularly in the case of the Ziegler-Natta catalyst, one can mention metal content determination by X-ray fluorescence spectrometry (XRF), 13,14 X-ray photoelectron spectroscopy (XPS), [12][13][14][15] and Rutherford backscattering spectrometry (RBS). 16,17 ...

show abstract

“…After a reaction with H 2 SO 4 , the contents of titanium, magnesium, and chloride in the MgCl 2 -supported Ziegler-Natta catalysts were determined by spectrophotometry, and by complexometric and argentometric titration, respectively. 33 The characterization results of the prepared solid catalysts are presented in Table I.…”

Section: Catalysts Characterization Chemical Analysismentioning

confidence: 99%

Propylene Polymerization over MgCl₂‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor

et al. 2016

View full text Add to dashboard Cite

1-Methoxy-2,2-bis(methoxymethyl)butane as a new internal donor was synthesized by the reaction of 1,1,1-tris(hydroxymethyl)propane with sodium hydride as the base and methyl iodide as the alkyl halide. The tri-ether compound was characterized by NMR and FTIR techniques. The MgCl 2 -supported titanium catalysts were incorporated with varying amounts of 1-methoxy-2,2-bis(methoxymethyl)butane as the internal donor (ID) and also without the internal donor were synthesized, and then the prepared catalysts were characterized. The concentration of titanium, magnesium, and chloride were determined by spectrophotometry and by complexometric and argentometric titration, respectively. The polymerization of propylene was carried out with the prepared catalysts in conjunction with triethylaluminum as a cocatalyst and hydrogen as a chain transfer agent, with and without cyclohexylmethyldimethoxysilane as the external donor. The effects of a new internal donor on MgCl 2 -supported Ziegler-Natta catalysts for propylene polymerization were investigated, and then these results were compared to the obtained polypropylenes results, which were obtained using the conventional Ziegler-Natta catalyst containing diisobutyl phthalate as the internal donor. The highest isotacticity, melting temperature, and crystallinity degree of polypropylene were obtained using Cat-D with an ID/Mg molar ratio equal to 0.44, and the highest catalytic activity is related to Cat-B with an ID/Mg molar ratio equal to 0.22. The Ziegler-Natta catalysts incorporated with various ID/Mg molar ratios of 1-methoxy-2,2-bis(methoxymethyl)butane were synthesized. The polymerization of propylene was carried out with the prepared catalysts. The highest catalytic activity is related to Cat-B with an ID/Mg molar ratio equal to 0.22. The catalyst with an optimum ID/Mg molar ratio equal to 0.44 is a favorable catalyst for polymerization of propylene. C

show abstract

Determination of Mg, Ti and Cl in Ziegler-Natta catalysts by WDXRF

Cited by 13 publications

References 19 publications

Cp2TiCl2 used as a catalyst for the transesterification between dimethyl carbonate and phenol to diphenyl carbonate

Cp2TiCl2 used as a catalyst for the transesterification between dimethyl carbonate and phenol to diphenyl carbonate

Determination of Titanium and Vanadium in Ziegler-Natta Catalysts by Inductively Coupled Plasma Atomic Emission Spectrometry

Propylene Polymerization over MgCl₂‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor

Contact Info

Product

Resources

About

Determination of Mg, Ti and Cl in Ziegler-Natta catalysts by WDXRF

Cited by 13 publications

References 19 publications

Cp2TiCl2 used as a catalyst for the transesterification between dimethyl carbonate and phenol to diphenyl carbonate

Cp2TiCl2 used as a catalyst for the transesterification between dimethyl carbonate and phenol to diphenyl carbonate

Determination of Titanium and Vanadium in Ziegler-Natta Catalysts by Inductively Coupled Plasma Atomic Emission Spectrometry

Propylene Polymerization over MgCl2‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor

Contact Info

Product

Resources

About

Propylene Polymerization over MgCl₂‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor