Methylaluminoxane
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. SBA-15 as a Support for Nickel-Based Catalysts for Polymerization Reactions
Two mesoporous SBA-15 materials with different morphologies (spherical and fiber-shaped) were synthesized and evaluated as supports for nickel-based catalysts for polymerization reactions. The supports were pretreated with trimethylaluminum (TMA), and the catalyst dibromo-bis(4-amino-2,3,5,6-tetramethylimino)acenaphthene nickel(II) was attached to the suppor
J. Braz. Chem. Soc.. Publicado em: 2018-02
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2. A New Post-Metallocene-Ti Catalyst with Maltolate Bidentade Ligand: an Investigation in Heterogeneous Polymerization Reactions in Different Mesoporous Supports
A new titanium catalyst easily synthesized from ethylmaltol bidentate chelator ligand was studied in homogeneous and heterogeneous ethylene polymerization. The dichlorobis(3-hydroxy-2-ethyl-4-pyrone)titanium(IV) complex was characterized by 1H and 13C NMR (nuclear magnetic resonance), UV-Vis and elemental analysis. Theoretical study by density functional the
J. Braz. Chem. Soc.. Publicado em: 2016-11
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3. Polyethylene-polyaniline Nanofiber Composites: Evaluation of Experimental Conditions of in situ Polymerization
The difficult processability of polyaniline (PAni) can be overcome by preparing composites with high density polyethylene (HDPE), resulting in a conducting material with improved mechanical properties. PAni nanofibers were synthesized in this research using a rapid mixing method, while HDPE/PAni composites were prepared by in situ polymerization using Cp2ZrC
Mat. Res.. Publicado em: 23/10/2015
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4. Polimerização de estireno utilizando compostos organolantanídeos ativados por MAO
In an attempt to improve the performance of organolanthanide catalysts we investigated the use of the industrially important cocatalyst methylaluminoxane (MAO) to activate organolanthanide compounds in olefin polymerization. The catalytic systems LnBrCp2(THF)2/MAO (Cp=cyclopentadienyl) and LnBrCp*2THF/MAO (Cp*= pentamethylcyclopentadienyl), Ln=Pr and Yb, wer
Química Nova. Publicado em: 2006-12
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5. Emprego de catalisadores à base de níquel para homo- e copolimerização de estireno
This review deals with the homo- and copolymerization of styrene with nickel catalysts. The catalytic activity, polymer stereoregularity, polymer molecular weight and polydispersity are dependent upon nickel ligands and reaction parameters. Catalysts supported on silica, treated with methylaluminoxane (MAO), have shown higher stereospecificity and activity c
Química Nova. Publicado em: 2004-12
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6. Olefin polymerization catalyzed by organolanthanide compounds / Polimerização de olefinas utilizando sistemas catalíticos à base de compostos organolantanídeos
Nas últimas décadas, o interesse nas propriedades específcas dos organolantanídeos está aumentando muito, principalmente no uso como catalisadores em diversas reações orgânicas. Com o objetivo de contribuir para a aplicação de compostos organolantanídeos como catalisadores nessas reações, avaliou-se o desempenho de sistemas catalíticos a base d
Publicado em: 2004
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7. Compostos organolantanídeos contendo o ligante pirazinamida: síntese, caracterização e atividade catalítica na polimerização do etileno
In this work we report the synthesis of some organolanthanide compounds which were identified as LnCl2Cp(PzA)2, Ln = Nd, Sm, Eu and Tb, Cp = cyclopentadienyl and PzA = pirazinamide, by elemental analyses, complexometric titration with EDTA, thermal analyses and IR spectra. Thermal analysis and infrared spectra indicated that the coordination of the pyrazinam
Química Nova. Publicado em: 2002-09
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8. Estudo de alguns compostos organolantanídeos como catalisadores na reação de polimerização de etileno / Study of some organolanthanide compounds as catalysis of ethylene polymerization reaction
In attempt to contribute to the application of organolanthanides as catalysts for olefin polymerization, we report the synthesis, characterization and catalytic activity in ethylene polymerization ofthe organolanthanide compounds containing or not the ligands triphenylphosphine (PPh3) and pyrazole (HPz). The synthesis of the organolanthanide compounds was pe
Publicado em: 2001
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9. An efficient and general route to reduced polypropionates via Zr-catalyzed asymmetric C—C bond formation
An efficient and general method for the synthesis of reduced polypropionates has been developed through the application of asymmetric carboalumination of alkenes catalyzed by dichlorobis(1-neomenthylindenyl)zirconium [(NMI)2ZrCl2]. In this investigation, attention has been focused on those reduced polypropionates that are α-monoheterofunctional and either �
National Academy of Sciences.