Results 11 to 20 of about 94,776 (218)

Síntese de catalisadores Ziegler-Natta: algumas rotas e suas dificuldades Synthesis of Ziegler-Natta catalysts: some routes and their difficulties

open access: yesQuímica Nova, 1997
The Ziegler-Natta catalyst and the polymerization thereof are systems which require careful handling and special treatment of chemicals. In spite of the use of inert atmosphere and dry chemicals, some Ziegler-Natta systems may present low activities or ...
Thaís H. S. Costa   +4 more
doaj   +2 more sources

Synthesizing polypropylene with percolation network catalyzed by inorganic nanoparticles-functionalized Ziegler-Natta catalyst [PDF]

open access: yesPolyolefins Journal
Polypropylene is one of the most widely used synthetic resins, which is mainly synthesized with Ziegler-Natta catalysts. In this paper, the functionalized Ziegler-Natta catalyst is applied to prepare high-performance polypropylene.
Tingting Yang   +3 more
doaj   +2 more sources

Organische Trägermaterialien für Ziegler-Natta-Katalysatoren

open access: yes, 2017
Ziel dieser Arbeit war die Entwicklung eines auf einem organischen Trägermaterial basierenden Ziegler-Natta-Katalysatorsystems, welches die erforderliche Fragmentierbarkeit in möglichst kleine Fragmente aufweist. Hierfür sah das Konzept dieser Arbeit eine direkte Bildung der aktiven Zentren auf fein dispergierten, Hydroxy-funktionalisierten Polystyrol ...
Nietzel, Sven Ingo
openaire   +5 more sources

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

open access: yesPolyolefins Journal, 2020
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.
Seyed Mehdi Ghafelebashi Zaranda   +1 more
doaj   +1 more source

The charge percolation mechanism and simulation of Ziegler-Natta polymerizations, part VI: Mechanism of ethylene polymerization by supported chromium oxide [PDF]

open access: yesJournal of the Serbian Chemical Society, 2007
Despite intensive research over the last 50 years, many questions concerning ethylene polymerization by supported chromium oxide are still unanswered. Hence, the very fundamental issues of this polymerization are discussed in this paper. It is shown that
Stoiljković Dragoslav   +4 more
doaj   +3 more sources

A Study on the Effect of Catalyst Types on Microstructure of Ethylene/1-Hexene Copolymer by Thermal Fractionation [PDF]

open access: yesعلوم و تکنولوژی پلیمر, 2015
Olefinic copolymers of ethylene/1-hexene were synthesized by three main types of supported catalysts, including Philips, Ziegler-Natta and metallocene catalysts, and the specific microstructural features delivered by each class of the catalysts were ...
Seyed Mohammad Mehdi Mortazavi
doaj   +1 more source

Transition Metal–(μ-Cl)–Aluminum Bonding in α-Olefin and Diene Chemistry

open access: yesMolecules, 2022
Olefin and diene transformations, catalyzed by organoaluminum-activated metal complexes, are widely used in synthetic organic chemistry and form the basis of major petrochemical processes.
Ilya E. Nifant’ev   +2 more
doaj   +1 more source

Polietileno: principais tipos, propriedades e aplicações [PDF]

open access: yesPolímeros, 2003
A estrutura de cada polímero tem influência direta sobre a sua densidade e suas propriedades mecânicas. Ramificações longas, como as presentes no polietileno de baixa densidade, por exemplo, aumentam a resistência ao impacto, diminuem a densidade e ...
Fernanda M. B. Coutinho   +2 more
doaj   +1 more source

A Mathematical Model for Investigating the Effect of Reaction Temperature and Hydrogen Amount on the Catalyst Yield during Propylene Polymerization [PDF]

open access: yesKemija u Industriji, 2019
In this study, the effect of reaction temperature and hydrogen amount, as the most effective process variables on the Ziegler-Natta catalysts yield during propylene polymerization, was investigated with the aid of a validated mathematical model.
Gholam Hossain Varshouee   +3 more
doaj   +1 more source

Addition of a second alcohol in magnesium ethoxide synthesis as a way to vary the pore architecture of Ziegler-Natta catalysts [PDF]

open access: yesPolyolefins Journal, 2015
In Ziegler-Natta olefin polymerization, the pore architecture of catalysts plays a crucial role in catalytic performances and polymer properties. While the type of preparation routes (such as chemical reaction and solution precipitation) greatly affects ...
Toshiaki Funako   +3 more
doaj   +1 more source

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