Results 51 to 60 of about 6,795 (264)

Caracterização de polietilenos lineares de baixa densidade I.: determinação do teor de ramificação por métodos espectroscópicos Linear low density polyethylene characterization - I.: spectroscopic methods for comonomer content determination

Polímeros, 2005
Os polietilenos lineares de baixa densidade (LLDPE) apresentam propriedades variando amplamente em função da concentração e do tipo de comonômero utilizado na copolimerização, além do tipo de catalisador.
Antonio C. Quental, Lilian S. Hanamoto, Maria I. Felisberti   +2 more
doaj   +1 more source

Gas fluidized bed polymerization. [PDF]

, 2017
Edição dos ...
GAMBETTA, R., NEUMANN, G. A., SECCHI, A. R.   +2 more
core  

Dimethylformamide Impurities as Propylene Polymerization Inhibito [PDF]

, 2023
This research study examined how the use of dimethylformamide (DMF) as an inhibitor af fects the propylene polymerization process when using a Ziegler–Natta catalyst.
González-Cuello, Rafael, Hernández Fernández, Joaquin, Ortega-Toro, Rodrigo   +2 more
core   +1 more source

Styrene Polymerization with Group III Metallocenes: A Generative and Interpretable Catalyst Design Strategy Combining Density Functional Theory and Machine Learning

ChemistryEurope, Volume 4, Issue 1, January 2026.
Machine‐learning methods are used to predict styrene binding energies and insertion barriers in a series of group III cationic catalysts. A generative algorithm based on these predicted data is provided to propose new catalysts. The rational design of group III metallocene catalysts for styrene polymerization remains a complex challenge due to ...
Stella Christodoulou, Etienne Dos Santos, Romuald Poteau, Laurent Maron   +3 more
wiley   +1 more source

Rapid Methylation of Aryl Bromides Using Air‐Stable DABCO‐Bis(Trimethylaluminum) via Nickel Metallaphotoredox Catalysis

Angewandte Chemie, Volume 137, Issue 33, August 11, 2025.
Herein, we report the use of bis(trimethylaluminum)‐1,4‐diazabicyclo[2.2.2]octane (DABAl‐Me3) as practical source of radicals for the introduction of valuable methyl groups to aryl bromides via a Nickel/metallaphotocatalytic cross coupling strategy.
Jonas Djossou, Andrea Aloia, Luca Capaldo, Demi D. Snabilié, Morgan Regnier, Jasper H.A. Schuurmans, Antonio Monopoli, Bas de Bruin, Timothy Noël   +8 more
wiley   +2 more sources

Heterogeneous Distribution of Entanglements in a Nonequilibrium Polymer Melt of UHMWPE: Influence on Crystallization without and with Graphene Oxide [PDF]

, 2016
In the past, studies have been performed to follow chain dynamics in an equilibrium polymer melt using low molar mass polymers. Here we show that in linear ultrahigh molecular weight polyethylene entanglements formed during or after polymerization are ...
Dario Romano, Ele L. de Boer, Ferry J. D., Kangsheng Liu, Sanjay Rastogi, Sara Ronca, Yefeng Yao   +6 more
core   +4 more sources

Selective Semi‐Hydrogenation of Acetylene using a Single‐Atom Cobalt on Carbon Nitride Photocatalyst with Water as a Proton Source

Small Methods, Volume 10, Issue 2, 22 January 2026.
A sustainable alternative to the energy‐intensive traditional thermocatalytic hydrogenation of acetylene to ethylene is reported. The catalyst is a cobalt single‐atom catalyst supported on carbon nitride that is powered by visible light, uses water as a proton source and demonstrates high selectivity, stability, and recyclability.
Anna Fortunato, Daniele Perilli, Alexandru Dron, Verónica Celorrio, Goran Dražić, Luka Ðorđević, Laura Calvillo, Cristiana Di Valentin, Francesca Arcudi   +8 more
wiley   +1 more source

Ziegler-Natta Catalyst Preparation Process: Influential Parameters on Particles Morphology and Activity of Catalyst in Propylene Polymerization [PDF]

علوم و تکنولوژی پلیمر, 2013
Different parameters including temperature and amount of titanium tetrachloride (TiCl4) were examined with respect to Ziegler-Natta catalyst morphology and the catalyst performance during its preparation process.
Hassan Arabi, Hossein Abedini, Hamid Dolatshahi, Gholam-Reza Nejabat   +3 more
doaj   +1 more source

Kinetic resolution of racemic {alpha}-olefins with ansa-zirconocene polymerization catalysts: Enantiomorphic site vs. chain end control [PDF]

, 2006
Copolymerization of racemic {alpha}-olefins with ethylene and propylene was carried out in the presence of enantiopure C1-symmetric ansa metallocene, {1,2-(SiMe2)2({eta}5-C5H-3,5-(CHMe2)2)({eta}5-C5H3)}ZrCl2 to probe the effect of the polymer chain end ...
Bercaw, John E., Byers, Jeffery A.
core   +1 more source

Structural Characterization of Electron Donors in Ziegler–Natta Catalysts [PDF]

The Journal of Physical Chemistry C, 2018
Ziegler-Natta catalysis is a very important industrial process for the production of polyolefins. However, the catalysts are not well-understood at the molecular level. Yet, atomic-scale structural information is of pivotal importance for rational catalyst development.
E. S. Merijn Blaakmeer, Giuseppe Antinucci, Andrea Correa, Vincenzo Busico, Ernst R. H. van Eck, Arno P. M. Kentgens   +5 more
openaire   +5 more sources