Ziegler-Natta catalysts for propylene polymerization – Interaction of an external donor with the catalyst

Authors

  • Ludmila Vorontsova Boreskov Institute of Catalysis SB RAS, Prospekt Akad. Lavrentieva 5, 630090, Novosibirsk, Russian Federation
  • Valentina Panchenko Boreskov Institute of Catalysis SB RAS, Prospekt Akad. Lavrentieva 5, 630090, Novosibirsk, Russian Federation|Novosibirsk State University, Pirogova Str. 2, 630090, Novosibirsk, Russian Federation
  • Vladimir Zakharov Boreskov Institute of Catalysis SB RAS, Prospekt Akad. Lavrentieva 5, 630090, Novosibirsk, Russian Federation|Novosibirsk State University, Pirogova Str. 2, 630090, Novosibirsk, Russian Federation
Abstract:

The interaction of the external donor (propyltrimethoxysilane - PTMS) with titanium-magnesium catalysts (TMCs) containing dibutylphthalate (DBP) as internal donor, which were prepared in different ways, was studied by chemical analysis and infrared diffuse reflectance spectroscopy (DRIFTS). The chemical composition of the catalysts after their interaction with heptane solutions of PTMS, PTMS/AlEt3 or AlEt3 during 1h at 70°C showed that this interaction led to removal of both TiCl4 and DBP from the catalysts. The fractions of DBP and Ti extracted, as well as the amounts of PTMS and AlEt3 bound, depended on the method of synthesizing the catalysts. DRIFT spectroscopy data concerning the state of DBP in the catalysts, before and after treatment with heptane solutions of PTMS or PTMS/AlEt3 during 1h at 70°C, showed that PTMS could substitute both TiCl4 and DBP, while adsorbing on coordinatively unsaturated Ti and Mg ions in the catalyst. The presence of AlEt3 played a key role in the interaction of PTMS with the catalyst. Activity data for propylene polymerization showed that treatment of TMC catalysts with PTMS before polymerization led to a sharp activity decrease due to deactivation of active sites, while the interaction of the catalyst with PTMS in the presence of AlEt3 led only to a slight decrease of activity, probably due to deactivation of non-stereospecific active centers.

Upgrade to premium to download articles

Sign up to access the full text

Already have an account?login

similar resources

ziegler-natta catalysts for propylene polymerization – interaction of an external donor with the catalyst

the interaction of the external donor (propyltrimethoxysilane - ptms) with titanium-magnesium catalysts (tmcs) containing dibutylphthalate (dbp) as internal donor, which were prepared in different ways, was studied by chemical analysis and infrared diffuse reflectance spectroscopy (drifts). the chemical composition of the catalysts after their interaction with heptane solutions of ptms, ptms/al...

full text

Study of Ziegler-Natta/(2-PhInd)2ZrCl2 hybrid catalysts performance in slurry propylene polymerization

Several types of hybrid catalysts are made through mixing of 4th generation Ziegler-Natta (ZN) and (2-PhInd)2ZrCl2  metallocene catalysts using triethylaluminum (TEA) as coupling agent. Response surface methodology (RSM) is used to evaluate the interactive effects of different parameters including amounts of metallocene and TEA and temperature on metallocene loading. Analyzing the amounts of Al...

full text

A Study of Ziegler–Natta Propylene Polymerization Catalysts by Spectroscopic Methods

Ziegler-Natta polymerization catalysts were characterized by a complex of surface- and bulk-sensitive methods (DRIFTS, XPS, ESR, and XAS = XANES + EXAFS). A diffuse-reflectance Fourier-transform IR spectroscopy (DRIFTS) study showed the presence of strong Lewis acid sites in different concentrations and absence of strong basic sites in the polymerization catalysts. X-ray photoelectron spectrosc...

full text

Chromium(III) Based Ziegler-Natta Catalysts for Olefin Polymerization

Four chromium based oxo-trinuclear carboxylate complexes were prepared by reacting chromium(III) nitrate nonahydrate with acetic acid and substituted carboxylic acids. They were characterized using infrared spectroscopy (FT-IR). Chromium content of the complexes was determined by titrimetry method. The chromium(III) monochloroacetate complex, [Cr3O(ClCH2COO)6.3H2O]NO3.3H2O in combination with d...

full text

Design of stereoselective Ziegler-Natta propene polymerization catalysts.

After five decades of largely serendipitous (albeit formidable) progress, catalyst design in Ziegler-Natta olefin polymerization, i.e., the rational implementation of new active species to target predetermined polyolefin architectures, has ultimately become a realistic ambition, thanks to a much deeper fundamental understanding and major advances in the tools of computational chemistry. In this...

full text

Determination of kinetic parameters for ethylene polymerization (with and without hydrogen) by Ziegler-Natta catalyst.

In this study, slurry polymerization kinetics of ethylene with TiCl4/Mg(OEt)2/AlR3 Ziegler-Natta catalysts in various conditions using the model of sum square error (SSE) (method I) and model of least square error (LSE) (Method II) was investigated. For this purpose the molecular weight distributions of the samples were deconvoluted to the minimum number of Flor...

full text

My Resources

Save resource for easier access later

Save to my library Already added to my library

{@ msg_add @}


Journal title

volume 4  issue 1

pages  87- 97

publication date 2016-01-01

By following a journal you will be notified via email when a new issue of this journal is published.

Hosted on Doprax cloud platform doprax.com

copyright © 2015-2023