Lignins
Mostrando 1-12 de 65 artigos, teses e dissertações.
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1. Evaluation of Lignins of Trunk and Roots from Citrus sinensis L. Osbeck: A Large Available Brazilian Biomass
Citrus biomass is a source of biobased products and presents extensive chemical diversity. Among the structural macromolecules, lignins have been used in resins, bioplastics, and nanoencapsulation. Brazil has a large source of lignins, which are orange trees removed from groves that need to be renewed. However, the knowledge about these lignins is limited an
J. Braz. Chem. Soc.. Publicado em: 2021-01
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2. Use of Lignins from Sugarcane Bagasse for Assembling Microparticles Loaded with Azadirachta indica Extracts for Use as Neem-Based Organic Insecticides
Microcapsules of sugarcane bagasse lignin loaded with organic extracts of neem (Azadirachta indica) were prepared and evaluated as potential bioinsecticides. Lignins were extracted and modified by oxidation and acetylation reactions providing different biopolymers. Afterwards, they were characterized through several analytical techniques. The formulations we
J. Braz. Chem. Soc.. Publicado em: 2017-01
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3. Materials produced from plant biomass: part III: degradation kinetics and hydrogen bonding in lignin
In this study Klason lignins from Eucalyptus grandis (LEUG) and Pinus taeda (LPIT) were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using the Kissinger method. Thermogravimetric results showed that LPIT had higher thermal stability and also higher act
Mat. Res.. Publicado em: 16/07/2013
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4. Sistemas modelos de formação de lignina utilizando recursos sintéticos e celulares de Eucalyptus grandis (Hill ex Maiden). / Systems models of lignin formation using synthetic and cellular resources of Eucalyptus grandis (Hill ex Maiden).
The main objective of this research was to work out models for the study of the lignification. Eucalyptus grandis seedlings were produced in vitro, and the stem segments explants were used to obtain friable callus. For such, the auxins tested were TDZ, 2,4-D, NAA and IAA. The treatments with 50,0 μM 2,4-D; 3,0 μM TDZ and in the absence of growth re
Publicado em: 2009
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5. Use of solutions hidrotrópicas in delignification of sugarcane cane bagasse / Uso de soluções hidrotrópicas na deslignificação do bagaço de cana-de-açúcar
The production of sugar, energy and ethanol from sugar cane is one of the most important activities of Brazil and generates a enormous quantity of bagasse which can be used to increase the ethanol production. In this sense, the study of sugarcane bagasse is a very important task, in both technical and scientific approaches. Thus, the pre-treatment of sugar c
Publicado em: 2009
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6. Systematic study of the reactions involved in the determination of lignin and holocellulose in bagasse and straw from sugar cane samples / Estudo sistemático das reações envolvidas na determinação dos teores de lignina e holocelulose em amostras de bagaço e palha de cana-de-açúcar
The analytical methods currently used for chemical characterization of lignocellulosic materials were developed for wood and are applied with minor modifications for sugar cane bagasse and straw analysis. The lack of specific methodology for these materials leads to inadequate results and hamper both the planning and the interpretation of results. Thus, the
Publicado em: 2009
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7. Obtenção e caracterização das blendas de ligninas (sulfonadas, bagaço de cana de açucar, eucalipto) e taninos com o poli(3-hidroxibutirato-co-3-hidroxivalerato)/PHBV / Obtaining and characterization of the blends of lignins (sulfonated, sugar cane bagasse, eucalyptus) and tannins with the poly(3-hydroxybutirate-co-3-hydroxyvalerate)/PHBV
A produção de plásticos sintéticos tem aumentado ano após ano, por ser barato, resistente, etc. Mas, os especialistas advertem que o lucro obtido na industrialização e comercialização dos plásticos não pode por em risco o futuro da humanidade. Os fatos demonstram que o planeta já foi prejudicado, principalmente a fauna e a flora marinha. A soluç
Publicado em: 2009
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8. Uso da pirólise acoplada à cromatografia gasosa e à espectrometria de massas na determinação da relação siringil/guaiacil em ligninas de clones de Eucalyptus spp / Use of the pyrolysis coupled with gas chromatography and mass spectrometry in the determination of the syringyl/guaiacyl ratio in Eucalyptus spp. clones lignins
A relação siringil/guaiacil (S/G) foi determinada em madeiras de seis diferentes clones de Eucalyptus cultivados em quatro regiões do estado brasileiro de Minas Gerais. As determinações foram realizadas por pirólise acoplada à cromatografia gasosa e à espectrometria de massas (Pi- CG/EM) e os resultados obtidos foram comparados à valores de referên
Publicado em: 2008
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9. Determinação da relação siringila/guaiacila da lignina em madeiras de eucalipto por pirólise acoplada à cromatografia gasosa e espectrometria de massas (PI CG/EM)
The use of analytical pyrolysis combined with gas chromatography/mass spectrometry (Py-GC/MS) to determine the syringyl/guaiacyl ratio (S/G) in lignins from Eucalyptus spp woods was investigated. Sample of E. grandis and "E. urograndis" wood, with and without extractives, were subjected to pyrolysis from 300 ºC to 600 ºC. The products that results from pyr
Química Nova. Publicado em: 2008
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10. Casca de arroz processada via enzimólise como fonte de carbono para produção de celulose por Acetobacter xylinum / Rice husk processed with hidrolityc enzimes as source of carbon for the production of bacterial cellulose by Acetobacter xylinum
Bacterial cellulose (BC) has been applied in the electronic industry and in medicine as a wound dressing film. However, the high manufacturing cost limits its wide-scale use. To reduce the costs of the process and obtain a differentiated product, this work proposes the use of rice husk as a substrate for the production of BC, since it consists of minerals, c
Publicado em: 2008
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11. Caracterização de ligninas de Eucalyptus spp. pela técnica de pirólise associada à cromatografia gasosa e à espectrometria de massas / Characterizing the lignins of Eucalyptus spp. by the pyrolysis technique associated to both gas chromatography and mass spectrometry
Lignin is one of the main wood components as well as the cellulose and hemicellulose. It is known that the composition of lignin relative to the amounts of unit syringyl (S) and guaiacyl (G) can affect the efficiency of the kraft pulping. Thus, this work was carried out to develop a methodology for the determination of the S/G relationship in the Eucalyptus
Publicado em: 2006
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12. Modulation of the lignification process for application of jasmonic acid and 2,4-dichlorophenoxyacetic acid in Eucalyptus urophylla S. T. Blake. / Modulação do processo de lignificação por aplicação de ácido jasmônico e ácido 2,4-diclorofenoxiacético em Eucalyptus urophylla S. T. Blake
Lignin is a important a biomacromolecule for several biologic process in plants, the most important process is to give necessary rigidity to keep the stem verticality, and water and minerals circulation. This research was carried out with Eucalyptus urophylla seedling and the result can help other biothecnological studies. In this research were applied diffe
Publicado em: 2005