Results 51 to 60 of about 700 (179)

MgCl2 Support Preparation Techniques and Their Effects on Ziegler-Natta Catalysts Performance in Propylene Polymerization [PDF]

علوم و تکنولوژی پلیمر, 2013
A primary adduct of MgCl2.3.3EtOH (A0) was prepared by melt quenching and then it was further dealcoholated by thermal and chemical methods. In thermal dealcoholation, two different support samples with MgCl2.2.7EtOH (A1) and MgCl2.1.8EtOH (A2) formulas ...
Najmeh Hadian, Mehdi Nekoomanesh-Haghighi, Shokoofeh Hakim, Naeimeh Bahri-Laleh   +3 more
doaj   +1 more source

“Naked” Divalent Metal Cations Stabilized by Weakly Coordinating Anions: Syntheses, Properties, and Emerging Applications

European Journal of Inorganic Chemistry, Volume 29, Issue 14, 14 May 2026.
The preparation of soluble and stable metal M2+ dications only stabilized by weakly coordinating anions, that is, M[WCA]2 salts, is an emerging field that, beyond its fundamental interest, holds promise in reactivity due to the high electrophilicity of the central M2+ center.
Samuel Dagorne, Béatrice Jacques, Geetika Gupta, Rudolf J. Wehmschulte   +3 more
wiley   +1 more source

Sixtieth Anniversary of Ziegler-Natta Catalysts and Stereospecific Polymerization [PDF]

Kemija u Industriji, 2015
This review article highlights the history of the discoveries of organometallic catalysts and stereospecific polymerization of α-olefins, dienes and a number of vinyl monomers by Karl Ziegler and Giulio Natta sixty years ago, their developments and ...
Janović Z. , Veksli Z.
doaj  

Ti+4 determination in Ziegler–Natta polymerization catalysts via UV‒vis spectroscopy method [PDF]

Polyolefins Journal
The determination of Ti+4 in Ziegler–Natta catalysts is highly relevant for industrial plants that use Ziegler–Natta (ZN) catalysts based on TiCl4 as a source of titanium.
Jonas Biagini, Joao Henrique dos Santos
doaj   +1 more source

Study of Ethylene Polymerization Kinetics by TiCl4/Mg(OC2H5)2 Catalyst and Determination of the Active Sites Concentration [PDF]

علوم و تکنولوژی پلیمر, 2008
Ethylene was polymerized in slurry phase over a TiCl4/Mg(OC2H5)2 catalyst activated by Al(C2H5)3. It was shown experimentally that mass transfer resistance has no effect on polymerization kinetics.
S. Hakim, M.M. Mortazavi
doaj   +1 more source

Process Modeling for Propylene Polymerization to Transfer Reaction Kinetics From Lab to Plant

Chemie Ingenieur Technik, Volume 98, Issue 5, Page 254-261, May 2026.
The modeling approach combines an industrial model for a fourth‐generation Ziegler–Natta catalyst with lab‐scale derived kinetics of a novel fifth‐generation catalyst. By transferring intrinsic kinetics across scales, polypropylene production can be predicted. Accurate melt flow rate prediction is only obtained with an additional adjustment.
Anna Konopka, Matthias Feigel, Johanna Fernengel, Maximilian Dochnahl, Richard W. Fischer, Olaf Hinrichsen   +5 more
wiley   +1 more source

Electron Microscopy Transfer System to Protect Atmosphere‐Sensitive Materials for Scanning Electron Microscopy Characterization

Microscopy Research and Technique, Volume 89, Issue 5, Page 759-768, May 2026.
SEM–EDX and XRD characterization confirm that pouches made from readily available aluminum foil, used in combination with a commercial cryo‐EM transfer system, effectively protect highly atmosphere‐sensitive and/or hygroscopic materials from contamination during transfer from inert environments to the SEM vacuum chamber.
Louis G. Corcoran, Ellen M. Monzo, Chinomso E. Onuoha, Shivasheesh Varshney, Han Seung Lee, Chris Frethem, Bharat Jalan, Alon V. McCormick, R. Lee Penn   +8 more
wiley   +1 more source

Study on the Effects of Temperature, Time and the Policy of Prepolymerization on Particle Morphology in Propylene Slurry Polymerization with Heterogeneous Ziegler-Natta Catalysts [PDF]

علوم و تکنولوژی پلیمر, 2007
The effects of temperature, time and the strategy of prepolymerization were studied on the morphology of polypropylene particles. propylene polymerization was carried out in slurry phase using 4th generation of Ziegler-Natta Catalyst, cyclohexylmethyl ...
G. Pircheraghi, S. Pourmahdian, M. Vatankhah   +2 more
doaj   +1 more source

Overcoming Challenges in 3D Printing of Polyolefins and Their Composites: A Review on Strategies for Improved Printability and Performance

Polymer Engineering &Science, Volume 66, Issue 5, Page 3100-3141, May 2026.
This review integrates the molecular fundamentals, key challenges, and mitigation strategies in polyolefin 3D printing, focusing on shrinkage, warpage, and adhesion control. It highlights material design approaches using recycled polyolefins and functional fillers to improve printability, mechanical properties, and sustainability in additive ...
Malik Hassan, Philip McMorran, Marwan Eid, Julia Blair, Amar K. Mohanty, Manjusri Misra   +5 more
wiley   +1 more source

Magnesium alkoxide precursor to Ziegler-Natta catalyst - emphasis on morphology studies through computer vision approach [PDF]

Polyolefins Journal
MgCl2 supported Ti catalyst is used in commercial propylene polymerization process. Morphology is a key performance determination parameter for polymer resins produced by commercial olefin polymerization process. Higher resin flowability and bulk density
Yogeshwar Thakare, Ajay Kothari, Saurabh Shinde, Pooja Kadam, Natarajan Venkateswaran, Virendrakumar Gupta   +5 more
doaj   +1 more source