Olefin Polymerization
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Atom Transfer Radical Polymerization of Methyl Methacrylate Mediated by Grubbs 1st and 2nd Generation Catalysts: Insight into the Active Species
Ruthenium benzylidene complexes were evaluated as catalysts in atom-transfer radical polymerization (ATRP) of methyl methacrylate (MMA) under different reaction conditions. The mechanism by which Grubbs 1st and 2nd generation catalysts mediate olefin metathesis has been studied, little is known regarding the mechanism of ATRP reaction promoted by these compl
J. Braz. Chem. Soc.. Publicado em: 2017-08
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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. New Isopropylmaltol - Ti Synthesis and its Use as a Catalyst for Olefin Polymerization
Este artigo mostra a síntese e caracterização do ligante isopropilmaltol obtido a partir do furfural e também um novo complexo diclorobis-(3-hidroxi-2-isopropil-4-pirona)titânio(IV) com estrutura cis. Dados de ressonância magnética nuclear de 1H, análise elementar e UV-Vis confirmam a formação do complexo. Este complexo foi estudado em reações de
J. Braz. Chem. Soc.. Publicado em: 2014-12
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4. Copolymerization of 1-hexene and 1-dodecene with 1,3-butadiene by a versatate/diisobutylaluminum hydride/t-butyl chloride catalyst system
The aim of this study was to incorporate an alpha-olefin (1-hexene or 1-dodecene) in a high cis polybutadiene chain, using a neodymium versatate/diisobutylaluminum hydride/t-butyl chloride catalyst system. The influence of alpha-olefin on polymerization reaction and polymer characteristics, using different weight ratios of butadiene/α-olefin, was evaluated.
Polímeros. Publicado em: 2014
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5. Efeitos eletrônicos e estéricos de ligantes ancilares: relação estrutura-reatividade em complexos do tipo [RuCl2(PPh3)x(amina)y] para polimerização de olefinas via metátese / Electronic and steric effects of ancillary ligands: structure-reactivity relationship in [RuCl2(PPh3)x(amine)y] complex types for ring opening metathesis polymerization of olefins
Os complexos do tipo [RuCl2(PPh3)2amina], amina = pip (1) ou pep (2), foram estudados como iniciadores catalíticos para reações de ROMP de NBE, NBD e oxaNBE-OMe e na ROMCP de NBE com NBD e oxaNBE-OMe com NBE. O complexo [RuCl2(PPh3)(pep)(isn)] (3) foi estudado na ROMP de NBE e NBD. Os complexos 2 e 3 são inéditos e suas caracterizações são discutidas
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/08/2011
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6. Synthesis and characterization of butadiene-1,3 and octene-1 copolymer prepared by a Ziegler-Natta catalyst based on neodymium
The aim of this work is to evaluate the influence of octene-1 incorporation in the polybutadiene chain on the polymerization reaction and polymer characteristics. Thus, copolymerization of butadiene-1,3 with octene-1 using a Ziegler-Natta ternary catalyst based on neodymium was performed. The weight ratios of butadiene-1,3/α-olefin 100/0, 99/1, 97/3, 95/5,
Polímeros. Publicado em: 01/11/2011
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7. Preparation and reative studies of catalytic systems based on zirconocenes, face to homo-and co-polimerization reation of etene / Preparação e estudo de reatividade de sistemas catalíticos, a base de zirconocenos, frente à reação de homo- e copolimerização de eteno
Catalytic systems based on zirconoces which are able to polymerize ethene have been studied. Structural modifications on the basic catalytic precursor, diphenylmethylidene(η5- cyclopentadienyl)(η5-9-fluorenyl) zirconium dichloride (5a) have been carried out. The catalytic precursors 5a and bis(para-fluorophenyl)methylidene(η5-cyclopentadienyl)
Publicado em: 2007
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8. 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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9. 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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10. 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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11. Estudos praticos e teoricos da influencia das bases de Lewis em polimerização e co-polimerização de olefinas por TiCL4/TiO2(reduzido)
Heterogeneization of titanium tetrachloride on chemically reduced titanium dioxide, developed in our group, has been used as a very active catalyst for ethylene polymerization. This catalytic system although polymerizing propylene with lesser activity , yields a polymer with low polydispersity , high molar mass and isotacticity of 78%. The isotacticity of th
Publicado em: 2000
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12. Estudo de novos suportes para catalisadores de ziegler-natta
ln this work titanium tetrachloride -TiCl4- was heterogenized in novel supports with the objective of producing new Ziegler-Natta heterogeneous cataIysts. The organic supports tested were: atactic poly(propylene) -aPP, natural rubber -NR, poly(vinylchloride) -PVC, poly(4-vinylpyridine) -P4VP- with 2% and 25% divinylbenzene (DVB) and the Merrifield polymer. T
Publicado em: 1992