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 70oC 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 70oC, 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.

Cite: Panchenko V.N. , Vorontsova L.V. , Zakharov V.A.
Ziegler-Natta Catalysts for Propylene Polymerization – Interaction of an External Donor with the Catalyst
Polyolefins Journal. 2017. V.4. N1. P.87-97. DOI: 10.22063/poj.2016.1385 РИНЦ ANCAN OpenAlex

Dates:

Submitted:	Jun 14, 2016
Accepted:	Sep 8, 2016
Published print:	Jan 1, 2017

Identifiers:

Elibrary:	35099704
Chemical Abstracts:	2018:486610
Chemical Abstracts (print):	168:502986
OpenAlex:	W2558750175

Citing:

DB	Citing
Elibrary	15
OpenAlex	12

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