Results 1 to 10 of about 360,310 (205)

Polypropylene Nanocomposites Attained by In Situ Polymerization Using SBA-15 Particles as Support for Metallocene Catalysts: Effect of Molecular Weight and Tacticity on Crystalline Details, Phase Transitions and Rheological Behavior [PDF]

open access: yesMolecules, 2023
In this study, nanocomposites based on polypropylene are synthesized by the in situ polymerization of propene in the presence of mesoporous SBA-15 silica, which acts as a carrier of the catalytic system (zirconocene as catalyst and methylaluminoxane as ...
Rosa Barranco-García   +8 more
doaj   +2 more sources

The Influence of Ziegler-Natta and Metallocene Catalysts on Polyolefin Structure, Properties, and Processing Ability [PDF]

open access: yesMaterials, 2014
50 years ago, Karl Ziegler and Giulio Natta were awarded the Nobel Prize for their discovery of the catalytic polymerization of ethylene and propylene using titanium compounds and aluminum-alkyls as co-catalysts.
Mohd Azlan Hussain   +2 more
exaly   +4 more sources

Highly Flowable Nano TiO2/Porous Organic Polymer (POP) Supports for Efficient Metallocene Catalysts [PDF]

open access: yesNanomaterials, 2020
Porous organic polymers (POPs) have proven to be an efficient support in the olefin polymerization catalyst field. In this paper, nano TiO2 beads were used to modulate the pore structure, bulk density, and surface morphology and flowability of the ...
Xiong Wang   +5 more
doaj   +2 more sources

Comparison of Ethylene/1-Hexene Copolymers Microstructures Synthesized by Homogeneous and Heterogeneous Metallocene Catalysts [PDF]

open access: yesعلوم و تکنولوژی پلیمر, 2013
The substituted (bis-2-PhIndZrCl2) and non-substituted (bis-IndZrCl2) indenylbased metallocene catalysts were synthesized and used in homogenous and heterogeneous forms for copolymerization of ethylene and 1-hexene.
Saeid Ahmadjo
doaj   +2 more sources

Developments of Chiral Metallocenes as Polymerization Catalysts [PDF]

open access: yesMolecules, 2005
This review article describes developments in chiral metallocenes as polymerization catalysts focusing on C2 symmetric ansa-zirconocene complexes. Selective synthesis of rac-isomers of ansa-zirconocenes are surveyed.
Takeshi Shiono, Yuushou Nakayama
doaj   +3 more sources

Immobilizing metallocene by solid polymethylaluminoxane “sMAO” for slurry-phase ethylene-1-hexene copolymerization [PDF]

open access: yesMATEC Web of Conferences, 2022
In the field of olefin catalytic polymerization, metallocene catalysts show higher activity than traditional Ziegler-Natta catalysts. In this study, benzoic acid catalyzed the controlled hydrolysis of trimethylaluminum (TMA) to methylaluminoxane (MAO ...
Wu Chaofan   +5 more
doaj   +1 more source

Substituent effect of Cp2TiCl2 catalyst for ethylene polymerization: A DFT study [PDF]

open access: yesPolyolefins Journal, 2023
The substituents on cyclopentadienyl (Cp) can regulate the electronic effect and hindrance of the active center in the metallocene catalyst. This modification can greatly change the catalytic activity of the catalyst and affect some features of the ...
Kefeng Xie   +5 more
doaj   +1 more source

High-Efficiency Mono-Cyclopentadienyl Titanium and Rare-Earth Metal Catalysts for the Production of Syndiotactic Polystyrene

open access: yesMolecules, 2023
Syndiotactic polystyrene (SPS) refers to a type of thermoplastic material with phenyl substituents that are alternately chirally attached on both sides of an aliphatic macromolecular main chain.
Bo Wen   +5 more
doaj   +1 more source

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

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

open access: yesPolyolefins Journal, 2015
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.
Gholam-Reza Nejabat   +7 more
doaj   +1 more source

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