Results 71 to 80 of about 81,401 (281)

Gas phase polymerization of ethylene with a silica-supported metallocene catalyst: influence of temperature on deactivation [PDF]

, 1997
Ethylene was polymerized at 5 bar in a stirred powder bed reactor with silica supported rac-Me2Si[Ind]2ZrCl2/methylaluminoxane (MAO) at temperatures between 40°C and 80°C using NaCl as support bed and triethylaluminium (TEA) as a scavenger for impurities.
Meier, G.B., Roos, P., Samson, J.J.C., Samson, Job Jan C., Weickert, G., Westerterp, K.R.   +5 more
core   +2 more sources

2,3‐Diboratabutadiene Complexes of Group 4 Metals and their Donor‐Induced Oxidative Cleavage to Methyleneboranes

ChemistryEurope, Volume 3, Issue 6, November 11, 2025.
GA: We here report the first perarylated 2,3‐diboratabutadiene dianion and its reaction with Cp2MCl2 (M = Zr, Hf) to afford unprecedented 2,3‐diboratabutadiene π‐complexes with unique coordination modes. Addition of an N‐heterocyclic carbene (NHC) to the complexes gives rise to the donor‐induced oxidation of the BB bond, resulting in two separate NHC ...
Philipp Grewelinger, Carsten Präsang, Bernd Morgenstern, David Scheschkewitz   +3 more
wiley   +1 more source

How can pH value during catalyst preparation affect the performance of vanadium-modified (SiO2/MgO/ MgCl2)•TiClx Ziegler-Natta polyethylene catalysts [PDF]

Polyolefins Journal, 2018
Vanadium-modified (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta catalysts were prepared through co-impregnation of water-soluble magnesium and vanadium salts under different pH values.
Ting Fu, Ruihua Cheng, Xuelian He, Zhen Liu, Zhou Tian, Boping Liu   +5 more
doaj   +1 more source

Direct Carboboration of Aryl Alkenes with Stable Organoborons Through Ziegler‐Type Addition

Advanced Science, Volume 12, Issue 43, November 20, 2025.
The direct carboboration of vinyl arenes with benzylic boronates has been achieved using KOtBu as the catalyst. Vinylcyclopropanes and vinylcyclobutane also participate in this reaction, yielding the corresponding 1,5‐ and 1,6‐carboboration products.
Mo Yang, Shengda Chen, Daojing Li, Liuzhou Gao, Guoqiang Wang, Shuhua Li   +5 more
wiley   +1 more source

Propylene–Ethylene Copolymer Covalent Adaptable Networks Synthesized by Resonance‐Stabilized, Radical‐Based Reactive Processing with Excellent Elevated‐Temperature Creep Resistance

ChemSusChem, Volume 18, Issue 20, October 23, 2025.
Propylene‐ethylene copolymer covalent adaptable networks (PEC CANs) are synthesized via one‐step, radical‐based reactive processing with the use of initiator, dynamic cross‐linkers, and vinyl aromatic additives. The best CAN suppresses over 98% of creep at 100 °C (semicrystalline state) for 10,000 s compared to neat PEC.
Yen‐Wen Huang, Mathew J. Suazo, Stephanie M. Barbon, Hayley A. Brown, Evelyn Auyeung, Colin Li Pi Shan, John M. Torkelson   +6 more
wiley   +1 more source

Ultrasound- and microwave-assisted preparation of lead-free palladium catalysts: effects on the kinetics of diphenylacetylene semi-hydrogenation [PDF]

, 2015
The effect of environmentally benign enabling technologies such as ultrasound and microwaves on the preparation of the lead-free Pd catalyst has been studied.
Bonrath, Werner, Borretto, Emily, Cherkasov, Nikolay, Cravotto, Giancarlo, Ibhadon, Alex O., Medlock, Jonathan, Wu, Zhilin   +6 more
core   +1 more source

A Practical Guide to Heterogeneous Catalysis in Hydrocarbon Transformations

Chemistry – An Asian Journal, Volume 20, Issue 20, October 17, 2025.
A focused overview of the catalytic processing of hydrocarbons to transform them into more valuable compounds is presented. This work is intended to assist BSc, MSc, and PhD students, as well as junior researchers, in selecting and performing appropriate heterogeneous catalytic processes for specific heterogeneous catalytic reactions.
Kelvin A. Sanoja‐Lopez, Alina M. Balu, Héctor de Paz Carmona, Martin Hájek, Rafael Luque, José Miguel Hidalgo Herrador   +5 more
wiley   +1 more source

Vapor Deposition of Polymer Structures: From 2D Surface Coatings and Surface Microstructures to 3D Building Blocks and Structural Monoliths

Macromolecular Rapid Communications, Volume 46, Issue 20, October 20, 2025.
This review discusses the progress of vapor‐deposited polymer structures, from simple thin films and surface microstructures to complex 3D architectures and monoliths. It covers fabrication methods, polymerization mechanisms, and processes for fabricating these structures. The applications of these polymers are discussed, focusing on device integration
Theresia Cecylia Ramli, Chung‐Ju Chen, Hui‐Hsuan Wang, Chi‐Yen Tsao, I‐Chen Hsu, Hung‐Jui Ting, Hsien‐Yeh Chen   +6 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