Esterification
Mostrando 25-36 de 392 artigos, teses e dissertações.
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25. Avaliação do tratamento térmico no catalisador magnético Ni0,5Zn0,5Fe2O4 e sua atividade catalítica na produção de biodiesel por transesterificação e esterificação simultânea do óleo de fritura
Resumo O objetivo deste trabalho foi avaliar o efeito do tratamento térmico na síntese do catalisador Ni0,5Zn0,5Fe2O4 e o desempenho catalítico em reações de transesterificação e esterificação simultânea (TES) do óleo de fritura. Os catalisadores foram sintetizados por reação de combustão sem e com tratamento térmico sequencial a 800 °C com t
Cerâmica. Publicado em: 2019-01
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26. Effect of the degree of acetylation, plasticizer concentration and relative humidity on cassava starch films properties
Abstract The objective of this study was to develop films with reduced hygroscopicity and improved mechanical properties from acetylated cassava starch. For that, an acetylation procedure using acetic anhydride as the esterification reagent was performed, resulting in starch acetates with degrees of substitution (DS) of 0.6 (S0.6) and 1.1 (S1.1). Twelve fil
Food Sci. Technol. Publicado em: 20/12/2018
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27. A Simple and High-yield Synthesis of Hexadecyl Ferulate and Its In Vitro Antioxidant Potential
ABSTRACT Ferulic acid (FA) is a phenolic compound with well-known antioxidant potential that can be used as a promising anti-inflammatory and anti-cancer molecule. Furthermore, it has been reported to have neuroprotective activity. One of the main problems, which limit its clinical use, is its low bioavailability when administered orally. This limitation can
Braz. arch. biol. technol.. Publicado em: 14/11/2018
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28. LEWIS ACID SITES OF Mg2+-MODIFIED POLYSTYRENE SULFONIC ACID RESIN CATALYSYS FOR SYNTHESIS OF DIBUTYL SUCCINATE
The polystyrene sulfonic acid resin catalysts were fabricated, containing elements of Cl and Mg through oxidization and impregnation, and they were characterized by EDS, FT-IR spectra, Py-IR spectra, UV spectra, XPS and TGA to investigate their physiochemical properties. The catalytic performances of these catalysts were examined in the esterification reacti
Quím. Nova. Publicado em: 2018-06
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29. ENZYMATIC BIODIESEL SYNTHESIS FROM ACID OIL USING A LIPASE MIXTURE
The conventional biodiesel production process has some disadvantages. It is necessary to use refined vegetable oils with low free fatty acids (FFAs) content. An alternative route is to use low-cost acid oils in an enzymatic process. The use of lipases allows simultaneous esterification of FFAs and transesterification of triglycerides present in raw material
Quím. Nova. Publicado em: 2018-03
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30. FATTY ACID ETHYL ESTERS FROM MICROALGAE OF Scenedesmus ecornis BY ENZYMATIC AND ACID CATALYSIS
Microalgae are an indispensable food source for the various growth stages of mollusks, crustaceans, and several fish species. Using a microalgae biomass present in the Amazonian ecosystem (Macapá-AP), we study extraction methods for fatty acid such as solvent extraction (magnetic stirring and/or Soxhlet) and/or hydrolysis (acid and/or enzymatic catalysis) f
Quím. Nova. Publicado em: 2018-01
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31. ESTERIFICAÇÃO E TRANSESTERIFICAÇÃO HOMOGÊNEA DE ÓLEOS VEGETAIS CONTENDO ALTO TEOR DE ÁCIDOS GRAXOS LIVRES
The high free fatty acids content in some vegetable oils can have a negative impact in the sustainable production of biodiesel. The previous treatment of these feedstock oils can contribute to the reduction of the process total costs as well as the environment, turning the biodiesel a more competitive in relation to the fossil diesel. The aim of this work wa
Quím. Nova. Publicado em: 2018-01
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32. Synthesis and Evaluation of Cytotoxic Effects of Amino-ester Derivatives of Natural α,β-Amyrin Mixture
Natural α,β-amyrins were isolated from endemic Brazilian Esenbeckia grandiflora Mart., and eight synthetic derivatives were obtained by esterification reactions with bromo acetate, followed by amine treatment. The structures of the all compounds were confirmed by 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and high-resolu
J. Braz. Chem. Soc.. Publicado em: 2017-11
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33. Nuclear Magnetic Resonance (1.40 T) and Mid Infrared (FTIR-ATR) Associated with Chemometrics as Analytical Methods for the Analysis of Methyl Ester Yield Obtained by Esterification Reaction
In this work, we compared 1.40 T nuclear magnetic resonance (NMR) to 7.05 T (60 and 300 MHz for proton, respectively), and mid-infrared with attenuated total reflectance (FTIR-ATR), associated with chemometrics methods, for the quantification of the reaction yield during esterification of fatty acids with methanol. The results showed that the integrated inte
J. Braz. Chem. Soc.. Publicado em: 2017-10
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34. Assessment of process variables on the use of macauba pulp oil as feedstock for the continuous production of ethyl esters under pressurized conditions
ABSTRACT This study evaluated the potential of macauba pulp oil (MPO) as a feedstock for continuous ester production using ethanol under pressurized conditions. Experiments were performed in order to obtain data for the effect of process variables on ethyl ester (FAEE) and free fatty acid (FFA) conversion in a catalyst-free process. From the results, it appe
Braz. J. Chem. Eng.. Publicado em: 2017-07
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35. Production of flavor esters catalyzed by lipase B from Candida antarctica immobilized on magnetic nanoparticles
Abstract Candida antarctica Lipase B (CALB) immobilized onto iron magnetic nanoparticles was evaluated as biocatalyst for the synthesis of flavor esters. Methyl and ethyl butyrate were synthesized by esterification of butyric acid with methanol and ethanol, respectively, in a medium containing solvent. The nanoparticles were produced by the co-precipitation
Braz. J. Chem. Eng.. Publicado em: 2017-07
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36. SÍNTESE ENZIMÁTICA DO CAPRILATO DE ISOPENTILA UTILIZANDO ÓLEO FÚSEL COMO MATÉRIA-PRIMA
Four commercial lipase preparations immobilized by covalent attachment on epoxy-polysiloxane-β-cyclodextrin were tested as potential biocatalysts to mediate the esterification reaction of isopentanol with caprylic acid in solvent-free medium. Among them, the immobilized lipase from Rhizopus oryzae was the most active biocatalyst, attained ester conversion h
Quím. Nova. Publicado em: 2017-06