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1.
Molecules ; 20(12): 21840-53, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26690107

RESUMO

Vegetable oils and fatty acid esters are suitable precursor molecules for the production of a variety of bio-based products and materials, such as paints and coatings, plastics, soaps, lubricants, cosmetics, pharmaceuticals, printing inks, surfactants, and biofuels. Here, we report the possibility of using Lewis acidic ionic liquids (ILs) to obtain polyunsaturated ester dimerization-oligomerization and/or, in the presence of another terminal alkene (propene), co-polymerization. In particular, we have tested the Lewis acidic mixtures arising from the addition of a proper amount of GaCl3 (Χ > 0.5) to two chloride-based (1-butyl-3-methylimidazolium chloride, [bmim]Cl, and 1-butylisoquinolium chloride, [BuIsoq]Cl) or by dissolution of a smaller amount of Al(Tf2N)3 (Χ = 0.1) in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [bmim][Tf2N]. On the basis of product distribution studies, [bmim][Tf2N]/Al(Tf2N)3 appears the most suitable medium in which methyl linoleate alkylation with propene can compete with methyl linoleate or propene oligomerization.


Assuntos
Ácidos Linoleicos/química , Alcenos/química , Alquilação , Gálio/química , Líquidos Iônicos/química , Ácidos de Lewis
2.
J Chromatogr A ; 1216(14): 2891-9, 2009 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-19010479

RESUMO

A detailed mass map of C(10)'s is required to better understand the mechanism of decalin catalytic ring opening/rearrangement. Conventional GC-FID or GC-MSD techniques could not accurately identify these isomers. Comprehensive two-dimensional gas-chromatography with MSD (GCxGC-MSD) proved to be a powerful tool for this purpose, due to its enhanced peak resolution. Analytical response quality was evaluated by the separation of two contiguous peaks and MS profile "clearness". This allowed fragmentation study for nearly pure species. Tentative attributions, based on fragmentation-rearrangement in the MSD environment, were made after confirming that MS data bases routinely mistake olefins for cyclo-alkanes.


Assuntos
Alcanos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Naftalenos/análise , Catálise , Isomerismo
3.
ChemSusChem ; 1(6): 548-57, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18702154

RESUMO

The activity of different platinum-loaded zeolites (Mordenite, ZSM-12, ZSM-5, ZSM-23) was investigated in the hydroconversion of methylcyclohexane (MCH), in the context of upgrading highly aromatic distillates for fuel blending. In all cases, conversion of MCH proceeds according to a pathway where the primary products are a mixture of dimethylcyclopentanes and ethylcyclopentane formed by isomerization and ring contraction of MCH. The primary products undergo consecutive ring-opening reactions with formation of n- and isoheptanes. The latter further react to form lower-molecular-weight n- and isoalkanes. The selectivity and distribution of products deriving from ring-contraction and ring-opening reactions are strongly affected by the pore size and topology of the zeolites. ZSM-5 exhibits a strong reactant shape-selectivity effect on ring-opening products. The evaluated zeolites show the following order of activity in the conversion of methylcyclohexane: Mordenite>ZSM-12>ZSM-5>ZSM-23.


Assuntos
Cicloexanos/química , Platina/química , Zeolitas/química , Catálise , Concentração de Íons de Hidrogênio , Porosidade
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