Results 61 to 70 of about 5,464 (221)

Polyethylene Melt Rupture and Slip in Simple Shear: A Visual and Mechanistic Study

Journal of Applied Polymer Science, Volume 143, Issue 3, January 15, 2026.
Slip velocity transient curve (left) with images of the specimen at different times during a simple shear experiment. On the right, schematics illustrate the sample and its side view before and after simple shear. ABSTRACT Melt rupture of a bimodal molecular weight distribution polyethylene is studied under simple shear via flow visualization ...
Mohammadali Sattari, Y. W. Inn, Paula M. Wood‐Adams   +2 more
wiley   +1 more source

TEMPO in Solution, Melted, Solid, and Adsorbed on a Silica Surface: A Paramagnetic NMR Study

Chemistry – A European Journal, Volume 32, Issue 1, 2 January 2026.
Paramagnetic species can often be measured with EPR and NMR spectroscopy. This is demonstrated using the important radical TEMPO. All 1H and 13C NMR signals of TEMPO could be recorded and assigned. The impact of TEMPO on the chemical shifts of solvent signals and a phosphine is described.
Ehsan Shakeri, Gabrielle E. Harmon‐Welch, Sara A. C. MacWade, Vladimir I. Bakhmutov, Janet Blümel   +4 more
wiley   +1 more source

Catalisadores metalocênicos: aspectos gerais e heterogeneização Metallocene catalysts: general aspects and heterogenization

Polímeros, 1998
Este trabalho apresenta uma discussão sobre aspectos gerais da nova tecnologia de síntese de polímeros com microestrutura e propriedades controladas, obtidos via sistema catalítico metaloceno/MAO.
Maria de Fátima V. Marques, Patricia Aragão C. Junior, Maria José C. Guimarães, Fernanda M. B. Coutinho   +3 more
doaj   +1 more source

Preparation of High-Purity Ammonium Tetrakis(pentafluorophenyl)borate for the Activation of Olefin Polymerization Catalysts

Molecules, 2021
Homogeneous olefin polymerization catalysts are activated in situ with a co-catalyst ([PhN(Me)2-H]+[B(C6F5)4]− or [Ph3C]+[B(C6F5)4]−) in bulk polymerization media. These co-catalysts are insoluble in hydrocarbon solvents, requiring excess co-catalyst (>3
Hyun-Ju Lee, Jun-Won Baek, Yeong-Hyun Seo, Hong-Cheol Lee, Sun-Mi Jeong, Junseong Lee, Chong-Gu Lee, Bun-Yeoul Lee   +7 more
doaj   +1 more source

Metallocene to metallocene conversion. Synthesis of an oxazoline-substituted pentamethyliridocenium cation from a ferrocenyloxazoline [PDF]

, 2016
Reaction of (S)-2-ferrocenyl-4-(1-methylethyl)oxazoline with [(CpIrCl2)-Ir-star](2) in benzonitrile with KPF6 and NaOH gave (eta(5)-(S)-2-(4-(1-methylethyl))oxazolinylcyclopentadienyl)(eta(5)-pentamethylcyclopentadienyl)-iridium(III) hexafluorophosphate (
Arrayás, Arthurs, Atkinson, Bildstein, Boyd, Christopher J. Richards, Ciancaleoni, Forissier, Gusev, Holland, Holtmann, Kang, Langheim, Long, McVey, Mohapatra, Moseley, Nishibayashi, Oxgaard, Peter N. Horton, Rausch, Reid, Richards, Ross A. Arthurs, Ruble, Sammakia, Schaarschmidt, Simon J. Coles, Stadlbauer, Struchkov, Suleimanov, Tenn, III   +31 more
core   +1 more source

Preparation and Reactivity of Anionic Iron Sandwich Complex Bearing π‐Phenol Ligand Acting as Proton‐Coupled Electron Transfer Reagent

Chemistry – An Asian Journal, Volume 21, Issue 1, January 2026.
Anionic Fe(I) sandwich complex bearing a π‐phenol ligand with a trifluoroborate substituent with an effective O−H bond dissociation free energy at 40.7 kcal/mol in tetrahydrofuran is prepared, which acts as a proton‐coupled electron transfer reagent for the reduction of organic substrates as well as a Mo(IV) nitride complex, leading to the formation of
Yoshiaki Tanabe, Soma Yamamoto, Shogo Kuriyama, Yoshiaki Nishibayashi   +3 more
wiley   +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

Enantioselective synthesis and application to the allylic imidate rearrangement of amine-coordinated palladacycle catalysts of cobalt sandwich complexes [PDF]

, 2013
The reaction of (η5-(N,N-dimethylaminomethyl)cyclopentadien-yl)(η4-tetraphenylcyclobutadiene)cobalt with sodium tetrachloropalladate and (R)-N-acetylphenylalanine gave planar chiral palladacycle di-μ-chloridebis[(η5-(Sp)-2-(N,N-dimethylaminomethyl ...
Cassar, Doyle J., Hughes, David L., Ilyashenko, Gennadiy, Ismail, Muhammad, Richards, Christopher J., Woods, James   +5 more
core   +1 more source

The Chemistry of Subphthalocyanines: Synthetic Strategies for their Axial, Peripheral, and Remote Postfunctionalization

ChemistryEurope, Volume 4, Issue 1, January 2026.
From axial and peripheral reactivity to remote derivatization, the chemical versatility of subphthalocyanines (SubPcs) renders them ideal scaffolds for the design of advanced functional materials. This review assembles the synthetic toolbox, key reaction conditions, and future challenges in SubPc functionalization, guiding the development of next ...
Marta Gómez‐Gómez, Juan Laforga‐Martín, Jorge Labrador‐Santiago, Jorge Labella, Tomás Torres   +4 more
wiley   +1 more source

Six-coordinated half-metallocene catalyst for ethylene polymerization and its mechanism study

Giant
The demand for catalysts capable of enabling olefin polymerization at elevated temperatures to meet industrial requirements continues to grow. Among emerging candidates, novel six-coordinated half-metallocene catalysts, which combine the advantages of ...
Qian Li, Zifang Guo, Shuzhang Qu, Xinwei Li, Jian Chen, Yiming Wei, Cui Zheng, Zhihui Song, Yue Lan, Zhao Wen, Chaofan Yu   +10 more
doaj   +1 more source