Fine Tuning of Catalyst Active Sites to Access Advanced Ultrahigh‐Melting Polyolefins
Angewandte Chemie, EarlyView.A redesign of the active site of the pyridylamido hafnium (Hf) catalysts can enhance the performance of this catalyst family and unlock previously inaccessible polymer structures. When the catalyst is precontacted with allyltrimethylsilane the active species is modified and the catalyst experiences a new life becoming able to polymerize sterically ...
Fabio De Stefano +3 more
wiley +2 more sources
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 +5 more
doaj +1 more source
Acyclic Hydrocarbon α,ω-Dienes: From Biomass and Plastic Upcycling to Carbocycles, Precision Polymers, and Cross-Linked Elastomers. [PDF]
ChemSusChemHydrocarbon α,ω‐dienes are mainly produced from steam‐cracking derivatives, but high costs, complexity, and environmental impact limit their use. This review highlights sustainable paths from biomass and plastic upcycling, and surveys catalytic transformations into carbocycles and specialty polymers, emphasizing their role as modular building blocks ...
Villaccio R, Leone G.
europepmc +2 more sources
Visible-Light Driven Acetylene Semi-Hydrogenation to Ethylene With a Copper Photosensitizer and a Cobaloxime Catalyst. [PDF]
ChemistryA fully noble‐metal‐free photocatalytic system that couples cobaloxime catalysis with Cu photosensitizer for HAT‐driven acetylene‐to‐ethylene conversion is reported. ABSTRACT The purification of ethylene streams from acetylene impurities remains a key industrial challenge, for which light‐powered strategies are emerging as sustainable alternatives to ...
Fortunato A +5 more
europepmc +2 more sources
Study of Ziegler-Natta/(2-PhInd)2ZrCl2 hybrid catalysts performance in slurry propylene polymerization [PDF]
Polyolefins 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
Ti+4 determination in Ziegler–Natta polymerization catalysts via UV‒vis spectroscopy method [PDF]
Polyolefins JournalThe 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
DIENES POLYMERISATION WITH METATHESIS AND ZIEGLER-NATTA HOMOGENEOUS CATALYSTS
, 1991 IN THIS THESIS THE POLYMERISATION OF DIENES WITH ZIEGLER-NATTA AND METATHESIS CATALYSTS IS DESCRIBED AND THE RELATION BETWEEN THE TWO TYPES OF POLYMERISATION IS EXAMINED.
Μπόκαρης, Ευθύμιος
core +1 more source
Historical and Philosophical Remarks on Ziegler-Natta Catalysts
, 1999 Part 1 outlines the complex, parallel historical evolution of Ziegler-Natta catalysts and related problems. In Part 2, as a general method of inquiry, chemical language and discourse are analyzed, at first to clarify chemists’ epistemic views and the ...
HYLE Publications, Luigi Cerruti
core +1 more source
The evolution of new generaton 'single-site' Ziegler-Natta polymerization catalysts [PDF]
, 2000 Since the discovery of stereospecific polymerization of olefins by K. Ziegler and G. Natta in 1955, tremendous developments have occurred in the area of designing polymerization catalysts.
Bajgur, Chandrasekhar S., Sivaram, S.
core +1 more source
Effects of Ti/Mg molar ratio on bi-supported SiO2/MgCl2 (ethoxide type)/TiCl4 catalysts in ethylene homopolymerization and ethylene/1-hexene copolymerization [PDF]
Polyolefins Journal, 2018 SiO2/MgCl2 (ethoxide type)/TiCl4 Ziegler-Natta catalysts for use in ethylene polymerization and ethylene/1-hexene copolymerization have been prepared using silica with a supported layer of magnesium ethoxide (Mg(OEt)2) as a catalyst precursor, followed ...
Liang Zhu +5 more
doaj +1 more source