Results 51 to 60 of about 6,733 (215)

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

Structure of a Permethylcyclopentadienyl-μ-tetramethylcyclopentadienylmethylene Scandium Dimer [PDF]

, 1992
Bis(η^5-pentamethylcyclopentadienyl)-bis[μ-2,3,4,5-tetramethyl-1-methylene-ScC^1:Sc'(η^5)-cyclopentadienyl]-discandium(III), [Sc_2(C_(10)H_(15))_2-(C_(10)H_(14)_2], M_r = 628.90, triclinic, Pl, ɑ = 8.641 (5), b= 9.478 (2), c = 12.338 (5) Å, ɑ = 75.58 (3),
Bercaw, John E., Hajela, Sharad, Schaefer, William P.   +2 more
core   +1 more source

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

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

Correlation Between Vinyl Content of Recycled HDPE and Polymer Degradation: An NMR Approach

Journal of Applied Polymer Science, Volume 142, Issue 47, December 15, 2025.
The degradation behavior of high‐density polyethylene (HDPE) during recycling depends on its vinyl group content. This study shows that 1H NMR spectroscopy enables accurate assessment of vinyl groups unlike FTIR. Changes in melt flow and molecular weight with multiple processing are linked to vinyl content which could enable tailor‐made re‐additivation
Kim Hao Ng, Frank Malz, Elke Metzsch‐Zilligen, Rudolf Pfaendner   +3 more
wiley   +1 more source

Nano-Dispersed Ziegler-Natta Catalysts for 1 μm-Sized Ultra-High Molecular Weight Polyethylene Particles

Frontiers in Chemistry, 2018
A catalytic approach to synthesize microfine ultra-high molecular weight polyethylene (UHMWPE) particles was proposed based on the exploitation of nano-sized catalysts.
Patchanee Chammingkwan, Yusuke Bando, Minoru Terano, Toshiaki Taniike   +3 more
doaj   +1 more source

Molecular Weight Distributions in Ideal Polymerization Reactors. An Introductory Review [PDF]

, 2011
The ultimate aim of polymerization reaction engineering is the production of polymers with tailor-made properties. An introductory review into this field is presented, with emphasis on the effects on the molar mass distribution (MMD), of the sought ...
Meira, Gregorio Raul, Oliva, H.
core