Epoxy Ring
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. DINÂMICA MOLECULAR REATIVA DA ABERTURA DO ANEL EPÓXI EM REAÇÕES COM POLIAMINA Ellen
The molecular dynamics simulations were used to study the epoxy ring-opening in the determination of kinetic parameters, with a temperature range from 1500 to 2500 K in a 20 x 20 x 20 Å unit cell containing 15 molecules of C2H4O (ethylene oxide) and 35 molecules of CH6N2 (methanediamine). The activation energy values for epoxy and diamine was 66 and 92 kJ m
Quím. Nova. Publicado em: 2020-05
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2. GRAPHENE OXIDE AND A GO/ZnO NANOCOMPOSITE AS CATALYSTS FOR EPOXY RING-OPENING OF EPOXIDIZED SOYBEAN FATTY ACIDS METHYL ESTERS
Abstract In this work, the grapheme oxide (GO) and GO/ZnO nanocomposite were successfully obtained from the oxidation of graphite and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). In the GO/ZnO nanocomposite, the GO sheets were coated with aggregated
Braz. J. Chem. Eng.. Publicado em: 09/12/2019
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3. New Limonoids from Dictyoloma vandellianum and Sohnreyia excelsa: Chemosystematic Considerations
Molecular phylogenetic studies separated and united a group of genera that constituted the Spathelia-Ptaeroxylon clade, in which Dictyoloma and Sohnreyia have been included. Our taxonomic interest in the Dictyoloma vandellianum and Sohnreyia excelsa stimulated an investigation of both species searching for limonoids. Leaves from D. vandellianum afforded the
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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4. Solvothermal Reduction of Graphite Oxide Using Alcohols
In the present work, we use either ethanol or ethylene glycol as reducing agents through the solvothermal method for graphite oxide reduction. A sulfuric acid treatment before the reduction process was also applied to evaluate its influence on the epoxy group ring-opening reaction. Reduced graphene oxide (RGO) samples were obtained with morphology like crump
Mat. Res.. Publicado em: 18/12/2017
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5. Mechanical Characterization of Basalt and Glass Fiber Epoxy Composite Tube
The application of basalt fibers are possible in many areas thanks to its multiple and good properties. It exhibits excellent resistance to alkalis, similar to glass fiber, at a much lower cost than carbon and aramid fibers. In the present paper, a comparative study on mechanical properties of basalt and E-glass fiber composites was performed. Results of app
Mat. Res.. Publicado em: 23/10/2017
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6. Proton conductive membranes based on poly (styrene-co-allyl alcohol) semi-IPN
The optimization of fuel cell materials, particularly polymer membranes, for PEMFC has driven the development of methods and alternatives to achieve systems with more adequate properties to this application. The sulfonation of poly (styrene-co-allyl alcohol) (PSAA), using sulfonating agent:styrene ratios of 2:1, 1:1, 1:2, 1:4, 1:6, 1:8 and 1:10, was previous
Polímeros. Publicado em: 10/06/2014
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7. Photoelastic analysis of stress generated by a silorane-based restoration system
Silorane-based composite, an epoxy material, was marketed as promising less polymerization contraction than conventional restorative materials. The aim of this study was to evaluate, by means of photoelasticity, the polymerization stress generated by a silorane-based composite. Thirty photoelastic rings with orifices measuring 5 mm (d) × 3 mm (h) were prepa
Brazilian Oral Research. Publicado em: 2011-08
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8. Síntese de insumos químicos a partir de biodiesel produzido pela transesterificação de gordura animal / Synthesis of intermediary chemicals produced from biodiesel by animal fat
Due to technical and economic reasons, the biodiesel production from animal fat, to be used as biofuel, is disadvantageous when compared to some processes that utilize raw materials from vegetables origin. However, biodiesel derived from animal fat has chemical characteristics that allow its use as an input for a wide range of products with high added value.
Publicado em: 2010
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9. Internal adaptation of cast titanium crowns
As the adaptation of titanium crowns obtained by Rematitan Plus investment, specific for titanium, is not recognized to be suitable, this study evaluated the effect of the concentration of the specific liquid and the temperature of the mold of investments on the internal misfit of crowns cast on commercially pure titanium. Individual dies of epoxy resin were
Journal of Applied Oral Science. Publicado em: 2007-08
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10. The solid-state and solution-state reassigned structures of tagitinin A, a 3,10-epoxy-germacrolide from Tithonia diversifolia, and the interconversion of 3,10-epoxy-germacrolide conformational families via a ring-atom flip mechanism
Tagitinina A(2), uma 3,10-epoxi-germacrolida-6,7-trans-lactona conhecida e isolada de Tithonia diversifolia foi estudada através de difração de raios-X de monocristal. Verificou-se que a mesma apresenta a configuração relativa 1beta,4alfa,6alfa,7beta,8beta que difere da orientação 1alfa em C(1) proposta originalmente na literatura e que foi determinad
Journal of the Brazilian Chemical Society. Publicado em: 2005-06
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11. As cumarinas do pterocaulon balansae, Chodat
Starting from an hexane/ethyl ether extract of the aereal parts of Pterocaulon balansae, Chodat, we isolated the five following coumarins: 5-(3 -methyl-2 ,3 -butenyloxy)-6,7-methylenedioxycoumarin; 5-(2 ,3 -epoxy-3 -methylbutyloxy)-6,7-methylenedioxycoumarin; 5-(2 ,3 -dihydroxy-3 -methylbutyloxy)-6,7-methylenedioxycoumarin; 6-methoxy-7-(2 ,3 -epoxy-3 -methyl
Publicado em: 1981
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12. The aba mutant of Arabidopsis thaliana is impaired in epoxy-carotenoid biosynthesis.
The three mutant alleles of the ABA locus of Arabidopsis thaliana result in plants that are deficient in the plant growth regulator abscisic acid (ABA). We have used 18O2 to label ABA in water-stressed leaves of mutant and wild-type Arabidopsis. Analysis by selected ion monitoring and tandem mass spectrometry of [18O]ABA and its catabolites, phaseic acid and