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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Nano-híbridos baseados em complexos de ftalocianina derivados do cardanol, óxido de grafeno e magnetita / Nano-hybrids based on phthalocyanine complexes derived from cardanol, graphene oxide and magnetite

Costa Júnior, Antônio Eufrazio January 2017 (has links)
COSTA JÚNIOR, Antônio Eufrázio. Nano-híbridos baseados em complexos de ftalocianina derivados do cardanol, óxido de grafeno e magnetita. 2017. 92 f. Tese (Doutorado em Química)–Universidade Federal do Cará, Fortaleza, 2017. / Submitted by José Orlando Soares de Oliveira (orlando.soares@bol.com.br) on 2017-09-26T12:04:05Z No. of bitstreams: 1 tese ANTONIO EUFRAZIO.pdf: 3689458 bytes, checksum: 342e0aa4ef754fd440716202f8541855 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-10-05T23:44:04Z (GMT) No. of bitstreams: 1 tese ANTONIO EUFRAZIO.pdf: 3689458 bytes, checksum: 342e0aa4ef754fd440716202f8541855 (MD5) / Made available in DSpace on 2017-10-05T23:44:04Z (GMT). No. of bitstreams: 1 tese ANTONIO EUFRAZIO.pdf: 3689458 bytes, checksum: 342e0aa4ef754fd440716202f8541855 (MD5) Previous issue date: 2017 / The phthalocyanines are synthetic macromolecules made up of planar heterocycles formed by four isoindole units linked by nitrogen through a nitrogen bridge. The aromatic rings of the macrocycle give the compound high density electronics due to one π conjugated system of 18 electrons. The main properties of phthalocyanines are: high thermal stability, photoconductivity, electric semiconduvidade, highly conjugated electronic structure, low solubility in a wide variety of organic solvents. This set allows its use and application; including its metal analogues in various industries like paint industry and pigments, photosensitizers, electronic sensors, photo catalysis, photodynamic therapy, photovoltaics, semiconductor and electronic systems that operate at low frequencies. Thus, aiming to make the most of optical and electrical properties of this class of molecules, this paper proposes synthesizing phtalocyanines derived from cardanol, the main by-product of agribusiness cashew nuts, and combines them with graphene oxide, material of high performance, doped with magnetic nanoparticles, producing new nanomaterials with high dielectric property. The phthalocyanines have been synthesized by two routes: conventional route and microwave irradiation. This one showed the highest yields compared the conventional method of 14.70; 9.59; 111.42 and 14.54% for the metallated phthalocyanines with Co, Cu, Ni and Zn, respectively. The products were characterized by the techniques 1H NMR, GC-MS, UV-Vis, FT-IR and TGA. The nanohybrids were characterized by FT-IR, TGA, DSC, their dielectric properties were verified by impedance spectroscopy and the magnetic behavior by hysteresis. For all nanomaterials studied, significant improvements were observed in the dielectric properties of nanohybrids when compared with the complexes analyzed separately. The magnetization values obtained for the hybrid materials were slightly lower than those of the pure magnetite. The lowest value found was 42 emu • g-1 (GO@Fe3O4/CoPc)) and 53.48% for GO@Fe3O4/NiPc. The nano-hybrids OG @Fe3O4/[Cu(Pc)] showed an increase in the values of permittivity and conductivity of 1,2 – 627 and 1.5 x 10-7 – 1.8 x 10-4 Ω-1 m-1. Therefore there was a real increase in the properties of de 5.2 x 104% (ε'r) e 2.7x 107 (σ) / As ftalocianinas são macromoléculas sintéticas constituídas de heterocíclicos planares, formadas por quatro unidades isoindol ligadas por nitrogênio através de pontes de azoto. Os anéis aromáticos do macrociclo conferem ao composto uma alta densidade eletrônica devido ao um sistema π conjugado de 18 elétrons. As principais propriedades das ftalocianinas são: elevada estabilidade térmica, fotocondutividade, semiconduvidade elétrica, estrutura eletrônica altamente conjugada, baixa solubilidade em uma grande variedade de solventes orgânicos. Esse conjunto permite sua utilização e aplicação, incluindo seus análogos metálicos, em diversos setores como indústria de tintas e pigmentos, fotosensibilizadores, sensores eletrônicos, fotocatálises, terapia fotodinâmica, células fotovoltaicas, semicondutores e sistemas eletrônicos que operam em baixas frequências. Assim, visando aproveitar ao máximo as propriedades ópticas e elétricas dessa classe de moléculas, este trabalho propõe sintetizar ftalocianinas derivado do cardanol, principal subproduto do agronegócio da castanha do caju, e combiná-las com óxido de grafeno, material de elevada performance, dopados com nanopartículas magnéticas, produzindo novos nanomateriais com elevadas propriedades dielétricas. As ftalocianinas foram sintetizadas por duas vias: via convencional e irradiação de micro-ondas. Este apresentou os maiores rendimentos quando comparados ao método convencional de 14,70; 9,59; 111,42 e de 14,54% para as ftalocianinas metaladas com Co, Cu, Ni e Zn respectivamente. Os produtos foram caracterizados pelas técnicas de RMN- 1H, GC-EM, UV-Vis, FT-IR, e TGA. Os nano-híbridos foram caracterizados por FT-IR, TGA, DSC, suas propriedades dielétricas foram verificadas por espectroscopias de impedância e o comportamento magnético por histerese. Para todos os nanomateriais estudados, foram observadas melhorias significativas nas propriedades dielétricas dos nano-híbridos quando comparados com os complexos analisados separadamente. Os valores de magnetização obtidos para os materiais híbridos foram ligeiramente menores do que os da magnetita pura. O menor valor encontrado foi de 42 emu • g-1 (OG@Fe3O4/CoPc) e de 53,48 emu • g-1para o OG@Fe3O4/NiPc. O nano-híbridos OG@Fe3O4/[Cu(Pc)], apresentou aumento noss valores de permissividade e de condutividade de 1,2 – 627 e 1,5 x 10-7 – 1,8 x 10-4 Ω-1 m-1. Portanto houve um aumento real nas propriedades de 5,2 x 104% (ε'r) e 2,7x 107 (σ)
12

Síntese e avaliação do perfil citotóxico de novas chalconas planejadas a partir do cardanol / Synthesis and cytotoxic evaluation of chalcones derived from cardanol

Oliveira, Andressa Souza 30 August 2016 (has links)
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências Farmacêuticas, 2016. / Submitted by Camila Duarte (camiladias@bce.unb.br) on 2016-10-21T15:26:22Z No. of bitstreams: 1 2016_AndressaSouzadeOliveira.pdf: 6087586 bytes, checksum: d6059fa5456fd4bc25014602787a059d (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-11-08T15:40:24Z (GMT) No. of bitstreams: 1 2016_AndressaSouzadeOliveira.pdf: 6087586 bytes, checksum: d6059fa5456fd4bc25014602787a059d (MD5) / Made available in DSpace on 2016-11-08T15:40:24Z (GMT). No. of bitstreams: 1 2016_AndressaSouzadeOliveira.pdf: 6087586 bytes, checksum: d6059fa5456fd4bc25014602787a059d (MD5) / O desenvolvimento de novos agentes baseados em produtos naturais tem sido intensamente explorado na busca de tratamentos mais eficazes para a farmacoterapia do câncer. As chalconas, importante grupo de produtos naturais, apresentam quimiodiversidade e propriedades biofarmacológicas convergentes a estes esforços. Descrevemos neste trabalho a síntese e avaliação de novas chalconas, como entidades químicas e misturas, planejadas a partir do líquido da casca da castanha do caju técnico. As metodologias sintéticas empregadas forneceram cinco intermediários em rendimentos que variaram de 70% a 90%. A partir do metóxipentadecilaldeído foram obtidas, em rendimento de 25% a 70%, nove chalconas, enquanto onze misturas de chalconas com cadeias insaturadas – monoeno (C8’-C9’), dieno (C8’-C9’ e C11’-C12’) e trieno (C8’-C9’, C11’-C12’ e C14’- C15’) – foram obtidas a partir das misturas de metóxipentadecenilaldeídos (9 misturas) e hidróxipentadecenilaldeídos (2 misturas) em rendimentos na faixa de 22% a 77%. Os intermediários e produtos finais foram avaliados em triagem inicial quanto ao potencial citotóxico por meio de ensaio colorimétrico nas linhagens adenocarcinoma prostático, carcinoma de cólon e glioblastoma. Para os quatro intermediários fenólicos e três misturas de chalconas que apresentaram percentual inibitório do crescimento celular igual ou superior a 75% em pelo menos duas linhagens testadas foram determinados os valores de IC50 frente a dez linhagens de células tumorais, fibroblasto murino (L929) e células mononucleadas do sangue periférico (PBMC). As chalconas selecionadas não promoveram hemólise a 200 μg/mL, enquanto duas mostraram melhor seletividade para HL60 e HCT116. Os estudos de relações estrutura-atividade revelaram a relevância dos grupos fenólicos como farmacofóricos para os intermediários e anel B das chalconas e auxofóricos para o anel A das diidroxichalconas e cadeias laterais insaturadas como arcabouços moleculares significativos para a otimização destes compostos. ________________________________________________________________________________________________ ABSTRACT / The development of new agents based on natural products has been extensively explored in the search for more effective treatments for cancer drug therapy. Chalcones, important group of natural products, have chemodiversity and bio-pharmacological properties convergent to these efforts. Herein, we describe the synthesis and evaluation of novel chalcones, as chemical entities and mixtures, designed from the technical cashew nut shell liquid. The employed synthetic methodology provided five intermediates in yields ranging from 70% to 90%. From the methoxypentadecylaldehyde were obtained, in 25% to 70% yields, nine chalcones with saturated alkyl chain, while eleven mixtures of chalcones with unsaturated alkyl chain – monoene (C8’-C9’), diene (C8’-C9’ and C11’-C12’), end triene (C8’-C9’, C11’-C12’ and C14’-C15’) – were obtained from the methoxytpentadecenylaldehydes (9 mixtures) and hydroxypentadecenylaldehydes (2 mixtures) in yields in the range from 22% to 77%. The intermediates and final products were evaluated in an initial colorimetric assay screening for the potential cytotoxic using three cell lines prostatic adenocarcinoma, colon carcinoma and glioblastoma. For the phenolic intermediates and three mixtures of chalcones, which exhibited inhibitory percentage of cell growth higher than 75% in at least two tested strains, were determined the IC50 values against ten tumor cell lines, murine fibroblasts (L929) and mononuclear cells from peripheral blood (MCPB). The selected chalcones did not promote hemolysis at 200 μg/mL, while dihydroxychalcones showed the best selectivity for HL60 and HCT116 cell lines. The studies of structure-activity relationships have shown the importance of phenolic groups, pharmacophoric for the intermediates and in the ring B of chalcones, and auxophoric for the ring A of the dihydroxychalcones and unsaturated side chain as significant molecular scaffolds for the optimization of these compounds.
13

Compostos organosselênio derivados da crisina e do cardanol: novas moléculas semi-sintéticas com atividades farmacológicas / Organoselenium compounds derived from Chrysin and Cardanol: nem semi-syntetic molecules with farmacological activities

Fonseca, Sergio Ferraz 07 July 2017 (has links)
Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2017-08-23T13:12:51Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese de doutorado Sergio Ferraz Fonseca.pdf: 3939876 bytes, checksum: 82b8a0029f316dd9c9495a7f795faf44 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-09-01T19:19:37Z (GMT) No. of bitstreams: 2 Tese de doutorado Sergio Ferraz Fonseca.pdf: 3939876 bytes, checksum: 82b8a0029f316dd9c9495a7f795faf44 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-09-01T19:19:37Z (GMT). No. of bitstreams: 2 Tese de doutorado Sergio Ferraz Fonseca.pdf: 3939876 bytes, checksum: 82b8a0029f316dd9c9495a7f795faf44 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-07-07 / Com a necessidade de encontrar fármacos mais potentes, são necessárias pesquisas que visam potencializar as atividades já presentes em compostos de origem natural através de metodologias que sejam as mais ecológicas e eficientes possíveis. O objetivo deste trabalho foi sintetizar compostos derivados da crisina 1 e do cardanol 3, contendo grupamentos organosselênio em suas estruturas, com o intuito de potencializar suas atividades farmacológicas. Os derivados da crisina foram sintetizados através de uma metodologia utilizando ultrassom como fonte de energia e iodeto de cobre como catalisador, obtendo-se seis novos compostos bis-selenilados., os quais foram obtidos em bons a ótimos rendimentos (60-89%) e posteriormente avaliados quanto às suas propriedades antioxidantes e antiproliferativas in vitro, onde foi possível observar que a presença de selênio aumentou ambas as propriedades da crisina. O composto com o grupo metila na posição orto apresentou os melhores resultados frente aos radicais DPPH (Imax: 39.79 µM) e ABTS+ (IC50: 6.5µM). No ensaio de Espécies Reativas (ERs), o mesmo apresentou alta atividade antioxidante no córtex de camundongos (IC50: 5.67 µM), enquanto o composto com o grupo metoxila foi mais ativo no hipocampo (IC50: 5.63 µM). Todos os compostos foram efetivos na prevenção da peroxidação lipídica, dando destaque para o composto contendo o átomo de flúor no teste com córtex (IC50: 0.54 µM) e o composto com o grupo metila no hipocampo (IC50: 0.27 µM). Além disso, o composto com flúor foi mais efetivo na inibição do crescimento de células tumorais pulmonares (A549), com um IC50 de 19.9 µM após 72 h, enquanto que o composto com grupo metoxila foi o mais efetivo após 48 h (IC50 of 41.4 µM). Em relação à síntese de derivados do cardanol 3, foi realizado um estudo para encontrar as melhores condições reacionais. Determinou-se que utilizando uma mistura de 3, disseleneto de difenila, m-CPBA como agente oxidante e ácido acético como solvente, com ultrassom como fonte de energia obteve-se o melhor resultado, com o produto desejado 37 em 25% de rendimento. A atividade antioxidante in vitro deste composto foi avaliada, e os resultados obtidos demonstram que o mesmo apresenta uma atividade antioxidante bastante promissora, com resultados superiores aos dos seus materiais de partida. / With the necessity of finding more powerful drugs, new researches are needed aiming to improve the pharmacological activities already present in natural compounds through the most ecological and efficient methodologies possible. The aim of this work was to synthesize new selenium-containing chrysin 1 and cardanol 3 derivatives in order to increase its’ biological activities. Chrysin derivatives were synthesize through a methodology using ultrasound as an energy source and cooper iodine as catalyst, achieving six new compounds with two organoselenium moieties, witch were obtained in good to excellent yields (60-90%) and after they were evaluated by their in vitro antioxidant and antiproliferative activities, where it was possible to see that the presence of selenium boosted both chrysin’s activities.The compound with a methyl group in the orto position presented the best results against the DPPH (Imax: 39.79 µM) and ABTS+ (IC50: 6.5µM) radicals. In the Reactive Species assay (RS), it presented high antioxidant activity in mice cortex (IC50: 5.67 µM), while the compound with the methoxyl group was more effective in the hippocampus (IC50: 5.63 µM). All compounds were effective against lipid peroxidation, highlighting the compound with the fluorine atom in the cortex assay (IC50: 0.54 µM) and the compound with the methyl group in the hippocampus assay (IC50: 0.27 µM). Besides, compound with the fluorine atom was more effective inhibiting lung cancer cells’ growth (A549), with an IC50 of 19.9 µM after 72 h, while the compound with the methoxyl group was more effective after 48h (IC50 of 41.4 µM). Regarding the synthesis of cardanol 3 derivatives, a study was performed in order to find the best reaction conditions. It was determined that by using a mixture of 3, diphenyl diselenide, m-CPBA as an oxidant agent and acetic acid as solvent, with ultrasound as energy source we achieved the best result, with the desired product 37 in 25% yield. The in vitro antioxidant activity of this compound was evaluated, and the obtained results reveled that this compound presents a very promising antioxidant activity, with superior results compared to its’ starting materials.
14

AvaliaÃÃo de antioxidantes aplicados à produÃÃo de biodiesel. / Evaluation of Applied Antioxidants to Biodiesel Production

Francisco Francielle Pinheiro dos Santos 23 July 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Este trabalho apresenta um estudo do comportamento e eficÃcia de antioxidantes aditivados ao biodiesel do Ãleo de soja. Os antioxidantes mais utilizados sÃo de estrutura fenÃlica, deste modo, sintetizar, comparar e estudar a aÃÃo destes antioxidantes avaliando as possÃveis causas que os levam a serem mais eficazes traz-nos informaÃÃes para a sÃntese de compostos com melhor atuaÃÃo antioxidante. Para uso como substrato orgÃnico, foi sintetizado o biodiesel a partir do Ãleo de soja, uma vez que à a partir deste, a produÃÃo de 81 % do biodiesel produzido no Brasil. Outro fator para o uso do Ãleo de soja à que este possui majoritariamente em sua composiÃÃo Ãcido linolÃico e olÃico, Ãcidos insaturados, altamente suscetÃveis à oxidaÃÃo. O biodiesel foi sintetizado atravÃs da reaÃÃo de transesterificaÃÃo com Ãlcool metÃlico, razÃo molar Ãlcool/Ãleo de 1:6 e hidrÃxido de sÃdio 0,5 % (m/m). As amostras de biodiesel foram aditivadas com os antioxidantes comerciais (BHT e ionol) e da biomassa (cardanol hidrogenado e cardanol alquilado) nas concentraÃÃes de 300, 600, 900, 1200, 1500, 2000, 3000 e 4000 mg/kg e armazenadas em frasco Ãmbar em uma temperatura de 22,  3 ÂC. Todas as amostras foram analisadas em teste de oxidaÃÃo acelerada (Rancimat), no tempo zero (momento logo apÃs a aditivaÃÃo) e apÃs 2, 4, 6, 9 e 12 meses de armazenamento. Durante o monitoramento observou-se a variaÃÃo do tempo de induÃÃo via rancimat em funÃÃo do tempo de armazenamento das amostras. As anÃlises tÃrmicas foram realizadas com o biodiesel do Ãleo de soja, BHT, ionol, cardanol hidrogenado, cardanol alquilado, e do biodiesel aditivado com estes antioxidantes nas concentraÃÃes de 300, 900, 1500, 3000 e 4000 mg/kg, na taxa de aquecimento de 10 ÂC/min, em atmosfera de nitrogÃnio, com faixa de aquecimento de 30 ÂC â 600 ÂC. AtravÃs da anÃlise tÃrmica verificaram-se o comportamento das amostras quando submetidas a temperaturas elevadas. As anÃlises por UV-vis foram realizadas com o intuito de avaliar o processo de autoxidaÃÃo das amostras apÃs 12 meses de armazenamento. Os experimentos via rancimat revelaram que os antioxidantes comerciais sÃo melhores que os da biomassa, os experimentos termogravimÃtricos e via UV-vis auxiliaram na constataÃÃo de que para otimizar antioxidantes fenÃlicos deve-se adicionar substituintes de baixo peso molecular nas posiÃÃes orto e para. AtravÃs dos resultados via Rancimat foi desenvolvido um software para a prediÃÃo do tempo de estabilidade oxidativa em funÃÃo do antioxidante utilizado, quantidade adicionada deste, tempo de armazenamento, bem como, realizar uma anÃlise econÃmica do custo de utilizaÃÃo de cada antioxidante. / This paper presents a study of the behavior and effectiveness of antioxidants additives for biodiesel from soybean oil. The most commonly used antioxidants are ofphenolic structure, thereby synthesizing, examining and comparing the antioxidant action for evaluating possible causes for a structure to be more effective when compared to another, brings forth necessary tools in the search for better performance antioxidant compounds. For use as an organic substrate, it was synthesized biodiesel from soybean oil, since this oil is from producing about 81 % of biodiesel produced in Brazil. Another factor for the use of soybean oil is that it has in its composition mainly oleic and linoleic acids, unsaturated acids highly susceptible to oxidation. The biodiesel was synthesized by the transesterification reaction with methyl alcohol, the molar ratio alcohol / oil of 1:6 and sodium hydroxide 0.5% (m / m). The biodiesel samples were doped with antioxidants (BHT and ionol), and biomass (hydrogenated cardanol and cardanol alkylated) at concentrations of 300, 600, 900, 1200, 1500, 2000, 3000 and 4000 mg.kg-1 and stored in an amber vial at a temperature of 22,  3  C. All samples were analyzed in an accelerated oxidation test (Rancimat), at the beginning (immediately after the moment additives) and after 2, 4, 6, 9 and 12 months storage. During monitoring the observed variation via Rancimat induction time as a function of storage time of the samples. The thermal analyzes were performed with biodiesel from soybean oil, BHT, ionol, hydrogenated cardanol, cardanolalkylated, and biodiesel doped antioxidants at concentrations of 300, 900, 1500, 3000 and 4000 mg.kg-1 rate heating to 10  C / min in a nitrogen atmosphere with heating range of 30  C - 600  C.Through thermal analysis verified the behavior of the samples when exposed to elevated temperatures. The analysis by UV-vis were conducted in order to evaluate the process of autoxidation of the samples after12 months of storage. The experiments via rancimat revealed that the commercial antioxidants are better than those of biomass, and to the thermogravimetric experiments via UV-vis the finding that helped to optimize phenolic antioxidants should be added low molecular weight substituent at the ortho and para positions. Through the results via Rancimat software was developed to predict the time depending on the oxidative stability of the antioxidant used, this added amount, time of storage and, perform an economic analysis cost of use of each antioxidant.
15

Development and application of nanostructured systems from the meso-porphyrin derived from LCC. / Desenvolvimento e aplicaÃÃo de sistemas nanoestruturados a partir da meso-porfirina derivada do LCC.

Claudenilson da Silva Clemente 23 June 2015 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Porphyrins are very attractive system to study self-assembly due to its basic structure, chemical and thermal stability, synthetic versatility and important technological applications. This work presents the development of self-assembled systems meso-porphyrin derived from cardanol, the major constituent of the LCC. We were developed Langmuir and Langmuir-Blodgett (LB) thin films and superparamagnetic nanosystems coated with meso-porphyrin. The Langmuir films showed molecular area mean of the 177 à 2 confirmed by compressibility modulus. The 700 nm band observed in the Langmuir films supports the coexistence of monomers and dimers similar to the spectra of the solution (CHCl3/CH3COOH). The Brewster angle microscopy measurements showed formation of bright block domains with different sizes and shapes for the monolayer that disappears after surface pressure starts to increase. The UVâvis spectra of the Langmuir films and FTIR reflection of the LangmuirâBlodgett films (LB) indicated that the molecules exhibit preferential orientation with the parallel planes to the water (Langmuir) and in the substrate (LB). The LB film of 5 layers showed better response as electrode and has been tested as a promethazine sensor. Magnetic Fe 3 O 4 nanoparticles with an average size of 11 nm were coated with oleic acid layer and a meso-porphyrin layer to producing a novel superparamagnetic fluorescent nanosystem. Also were obtained systems coated with meso-porphyrins metallated with Co2+, Ni2+, Cu2+ and Zn2+ ions. The systems were characterized by TEM, FT-IR, TGA, vibrating sample magnetometry, UV-Vis, fluorescence and confocal miscroscopy. The systems showed good thermal stability, excellent magnetization and nanosized dimensions. / Porfirinas sÃo sistemas muito atrativos para estudos de automontagem graÃas a suaestrutura ba se, estabilidadequÃmica e tÃrmica, versatilidade sintÃtica e importantes aplicaÃÃes tecnolÃgicas. Este trabalho tem por finalidade apresentar o desenvolvimento de sistemas automontados da meso-porfirina derivada do cardanol, constituinte majoritÃrio do LCC. Foram desenvolvidos filmes finos de Langmuir e Langmuir-Blodgett (LB) e aplicado como sensor eletroquÃmico para prometazina e nanossistemas superparamagnÃticos revestidos com a meso-porfirina. Os filmes de Langmuir apresentaram Ãrea molecular mÃdia de 177 à 2 , confirmado pelo mÃdulo de compressibilidade. A banda centrada em λ = 700 nm observados nos filmes suporta a coexistÃncia de monÃmeros e dÃmeros semelhantes aos espectros em soluÃÃo de CHCl3/CH3COOH. A microscopia do Ãngulo de Brewster mostrou domÃnios com blocos brilhantes de diferentes tamanhos e formas para a monocamada que desapareceram apÃs o aumento da pressÃo de superfÃcie. Os espectros de UV-vis dos filmes e FT-IR no modo reflexÃo dos filmes de Langmuir-Blodgett (LB) indicaram que as molÃculas apresentam orientaÃÃo preferencial com os planos paralelos à Ãgua (no Langmuir) e no substrato (LB). O filme LB de 5 camadas apresentou melhor resposta como eletrodo e foi testado como um sensor de prometazina. As nanopartÃculas magnÃticas de Fe 3 O 4 com tamanho mÃdio de 11 nm foram revestidos com uma camada de Ãcido oleico seguido da meso-porfirina produzindo um novo nanossistema superparamagnÃtico fluorescente. Foram obtidos tambÃm os sistemas revestidos com porfirinas metaladas com os Ãons Co2+, Ni2+, Cu2+ e Zn2+, os quais foram caracterizados por MET, FT-IR, anÃlise termogravimÃtrica, magnetometria de amostra vibrante, UV-Vis, emissÃo de fluorescÃncia e miscroscopia confocal. Os resultados mostraram que os sistemas apresentaram boa estabilidade tÃrmica, comportamento superparamagnÃtico e dimensÃes nanomÃtricas.
16

Propriedades ReolÃgicas e ResistÃncia a OxidaÃÃo de Cimento AsfÃltico de PetrÃleo (CAP) Modificado com Cardanol / Rheological Properties and Resistance to Oxidation of Petroleum Asphalt Cement (PAC) Modified with Cardanol

AntÃnio AurÃlio Gomes Moreira 11 February 2013 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / Neste trabalho, um derivado fenÃlico extraÃdo do lÃquido da casca da castanha de caju (LCC), fonte natural e renovÃvel, foi utilizado como aditivo modificador de cimento asfÃltico de petrÃleo (CAP). FraÃÃes extraÃdas por diferentes mÃtodos (I, II e III) foram analisadas por cromatografia lÃquida de alta eficiÃncia (HPLC) e por espectroscopia no infravermelho, tendo sido identificadas como cardanol. Os CAP modificados por cardanol (I) foram comparados ao CAP modificado por LCC e estireno-butadieno-estireno (SBS), sendo avaliadas suas propriedades reolÃgicas antes e apÃs envelhecimento simulado. O LCC e o cardanol (I) atuaram de forma semelhante, aumentando os valores de penetraÃÃo e reduzindo o ponto de amolecimento, a viscosidade, a temperatura de usinagem e compactaÃÃo (TUC), e a susceptibilidade tÃrmica do ligante. Os parÃmetros reolÃgicos, obtidos em reÃmetro de cisalhamento dinÃmico (DSR), indicaram que LCC e cardanol (I) tornaram o CAP mais susceptÃvel à deformaÃÃo permanente, no entanto, nÃo houve alteraÃÃo do desempenho do CAP a baixas temperaturas. Foi verificado que o cardanol pode atuar como agente compatibilizante de CAP modificado com SBS, tal como os Ãleos aromÃticos comerciais. Em relaÃÃo ao CAP original, o CAP com SBS apresentou diminuiÃÃo na penetraÃÃo e na susceptibilidade tÃrmica, e aumento do ponto de amolecimento e da viscosidade. Os parÃmetros reolÃgicos (G*, δ) indicaram que o CAP com SBS foi mais resistente à deformaÃÃo permanente. O efeito dos aditivos em relaÃÃo ao grau de desempenho (PG), a altas temperaturas, para os CAP modificados foi CAP/SBS > CAP/cardanol ≥ CAP/LCC. O PG, a baixas temperaturas, foi superior para CAP/SBS, indicando que este pode ser aplicado em regiÃes de clima frio. A resistÃncia à decomposiÃÃo tÃrmica, observada por termogravimetria (TGA), foi semelhante para todas as amostras. As curvas de calorimetria exploratÃria diferencial (DSC) mostraram que todas as amostras possuem baixo teor de fraÃÃes cristalizÃveis e que o CAP modificado com cardanol apresenta maior resistÃncia ao trincamento tÃrmico. O efeito de cardanol como potencial antioxidante foi avaliado apÃs o envelhecimento em estufa RTFOT, e por espectroscopia no infravermelho (FTIR). Os resultados indicaram que o cardanol foi Ãtil para atuar como aditivo redutor do envelhecimento do CAP. Na preparaÃÃo de corpos de prova de misturas CAP/cardanol e agregado constatou-se uma economia no teor de ligante requerido, comparando-se com o CAP sem aditivo. No ensaio Lottman modificado, foi verificado que o cardanol agiu como melhorador da adesividade (AMA) entre ligante e agregado, conforme medida da resistÃncia à traÃÃo (RRT) acima de 80%, e acima do valor encontrado para o CAP virgem. / In this work, phenolics from renewable and natural sources extracted from cashew nut shell liquid (CNSL) were used as petroleum asphalt cement (PAC) modifiers additives. Fractions extracted by different methods (I, II and III) were analyzed by High Performance Liquid chromatography (HPLC) and Infrared Spectroscopy (FTIR) and were identified as cardanol. The PAC modified by cardanol I was compared to PAC modified with CNSL and styrene-butadiene-estyrene (SBS) by measuring its rheological properties before and after an aging simulation evaluation. CNSL and cardanol I showed, similarly, increasing values of penetration and decreasing the soft point, the viscosity, the mixing and compaction temperature and the thermal susceptibility. Regarding the rheological parameters obtained by dynamic shear rheometer (DSR), it was observed that PAC/CNSL and PAC/cardanol became more susceptible to rutting. It was verified that cardanol acted as a compatibility agent in PAC modified with SBS in a similar way as for commercial aromatics oils. On the other hand, PAC modified with SBS showed decreasing on penetration values and on thermal susceptibility, as well as increasing soft point and viscosity values. PAC modified with SBS was more resistant to rutting as observed by its rheological parameters (G*, δ). The performance grade (PG) in high temperatures was lower for PAC/cardanol I and PAC/CNSL then for PAC modified with SBS, confirming the conclusions obtained by analysis of the rheological parameters. The PG value, in low temperatures, was greater for PAC modified with SBS then those for the other modified PAC, indicating that this mixture can be used in cold climates. For PAC modified with cardanol I and with CNSL, there was no change performance in low temperatures. The resistance to thermal degradation verified by thermogravimetry (TGA) was similar for all samples. The differential scanning calorimetry (DSC) showed that all samples have low content of crystallizable fractions and PAC modified by cardanol has a higher thermal crack resistance. Simulated oxidative ageing showed that cardanol acted as antioxidants. For the dosage of PAC modified with cardanol II, it was observed an economy in the content of used binder compared to PAC without any additive. In the Lottman modified test it was verified that cardanol II acted as an anti-stripping agent (ASA) between the binder and aggregates because it was found a tensile strength ratio (TSR) higher than 80% and larger than the value found for unmodified PAC.
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S?ntese e caracteriza??o de novo antioxidante fen?lico derivado da biomassa da castanha de caju (LCC-t?cnico) para biodiesel por m?todo eletroanal?tico

Falc?o, H?lson Ricardo da Cruz 18 February 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-17T18:51:44Z No. of bitstreams: 1 HelsonRicardoDaCruzFalcao_TESE.pdf: 4151566 bytes, checksum: d1da3c2cb8885e99219ae23d6bb3ffda (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-17T21:08:11Z (GMT) No. of bitstreams: 1 HelsonRicardoDaCruzFalcao_TESE.pdf: 4151566 bytes, checksum: d1da3c2cb8885e99219ae23d6bb3ffda (MD5) / Made available in DSpace on 2017-02-17T21:08:11Z (GMT). No. of bitstreams: 1 HelsonRicardoDaCruzFalcao_TESE.pdf: 4151566 bytes, checksum: d1da3c2cb8885e99219ae23d6bb3ffda (MD5) Previous issue date: 2016-02-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A maior parte da energia consumida no mundo deriva dos combust?veis f?sseis, como carv?o e petr?leo, tornando-a limitada. A energia ? a base fundamental das atividades humanas. Sejam elas, dom?sticas, comerciais, industriais, produ??o de alimentos ou agricultura. E, de acordo com a ?tica ambiental faz-se necess?rio reduzir o consumo por combust?veis f?sseis e aumentar o uso por combust?veis alternativos. Logo, o biodiesel surge como substituto promissor dos combust?veis f?sseis, sendo um biocombust?vel derivado de oleaginosas ou gorduras animais composto por ?steres alqu?licos que podem substituir total ou parcialmente o diesel em motores ciclodiesel. Todavia, quando derivado de oleaginosas ? suscept?vel a degrada??o oxidativa atrav?s de rea??es mediadas por calor e tra?os de metais, principalmente na presen?a de oxig?nio. Hoje, a maior parte de todo biodiesel produzido no Brasil, deriva da soja, que possui em m?dia 55% ?cido linoleico (18:2) e 7,5% de ?cido linol?nico (18:3) em sua composi??o, degradando o biocombust?vel. Este trabalho ? um estudo dos antioxidantes derivados do l?quido da castanha de caju - LCC t?cnico, com intuito de utiliz?-los diretamente como antioxidantes no biodiesel, a fim de melhorar sua estabilidade frente ? oxida??o. Realizou-se a extra??o dos componentes do LCC t?cnico e sintetizou-se os antioxidantes por via eletroqu?mica, que posteriormente foram caracterizados atrav?s das t?cnicas FT_IR, RMN 1H, CG_MS, eletroqu?micas e termogravim?tricas. Os resultados mostraram que s?o antioxidantes de baixo custo de produ??o, sol?veis em biodiesel e possuem alta estabilidade t?rmica, em torno de 220 ?C, assim como alta estabilidade termo-oxidativa, realizada no Rancimat, com potenciais de indu??o superior a 7h, tornando-os promissores e op??es efetivas de serem utilizados como aditivos em biocombust?veis. Atrav?s das t?cnicas eletroqu?micas verificou-se que o material apresenta uma adsor??o irrevers?vel sobre o eletrodo de platina utilizado. Al?m de um pico an?dico na primeira varredura e ainda uma oxida??o irrevers?vel com um potencial caracter?stico da atividade antioxidante aproximadamente entre +0,6 e +1,0V. / Most of the energy consumed in the world is derived from fossil fuels such as coal and oil, making it limited. Energy is the fundamental basis of human activities. Be they domestic, commercial, industrial, food production or agriculture. And, according to the environmental view point it is necessary to reduce consumption of fossil fuels and increased use of alternative fuels. Soon, biodiesel appears as promising substitute for fossil fuels, being a biofuel derived from oil or animal fats composed of alkyl esters that can replace all or part diesel engines in ciclodiesel. However, when oil derivative is susceptible to oxidative degradation by heat mediated reactions, and traces of metals, especially in the presence of oxygen. Today, most of all biodiesel is derived from soybean in Brazil, which has on average 55% linoleic acid (18:2) and 7.5% linolenic acid (18:3) in its composition, degrading the biofuel. This work is a study of antioxidants derived from cashew nut liquid - technical CNSL, aiming to use them directly as antioxidants in biodiesel in order to improve their stability to oxidation. We carried out the extraction of the components of technical CNSL and electrochemical synthesis of the antioxidant pathway, which were later confirmed using techniques FT-IR, NMR 1H, GC-MS, electrochemical and TG. The results show that antioxidants are low production costs, biodiesel-soluble, have high thermal stability at around 220?C as well as high thermo-oxidative stability, the Rancimat performed with higher potential induction 7h, making promising and effective options to be used as additives for biofuels. Through the electrochemical techniques, it was found that the material exhibits an irreversible adsorption on the platinum electrode used. In addition to an anodic peak in the first scan and even an irreversible oxidation with a characteristic potential of antioxidant activity in about +0,6V and +1,0V.
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A study of the mannich reaction with certain phenols, of the causes of formation of coloured products and the prevention of their occurence

Patel, Mahesh January 1979 (has links)
Mannich bases from dimethylamine, formaldehyde and phenol, m-cresol, eugenol, p-tent-pentylphenol, p-tert butylphenol, p-iso-propylphenol, 3,1,5-trimetbylphenol, resorcinol, 3-pentadecylphenol and the component phenols of cashew nut shell liquid (CNSL) have been prepared. Mannich bases have also been prepared from methylamine, formaldehyde with phenol and with m-cresol, from diethylenetriamine, formaldehyde and phenol, m-cresol, resorcinol, 3-pentadecylphenol and the component phenols of CNSL. A11 the Mannich bases were examined by H nuclear magnetic resonance, infra-red spectroscopy and by T. L. C. The coloured products formed from autoxidation of resorcinol, orcinol and hydrolr-ß-orcinol in presence of ammonia, methylamine and dimethylamine were isolated by column chromatography and preparative TLC and examined by 1H NMR, I. R, U. V. and mass spectroscopy. Structures of some of the products have been proposed based on chemical and spectroscopic evidence. A new technique for the separation of cardanol and cardol in cashew nut shell liquid by extractive distillation using bases has been devised.
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Valorisation du cardanol et d’acides et d’aldéhydes lipidiques dans le domaine des matériaux polymères / Valorization of cardanol and lipidic acids and aldehydes in the field of polymer materials

Briou, Benoît 05 October 2018 (has links)
L’un des défis majeurs dans le domaine des polymères est la substitution des molécules pétro-sourcées en vue de l’élaboration de monomères, polymères et d'additifs pour polymères. Le travail de cette thèse s’axe sur la valorisation de molécules bio-sourcées et plus particulièrement, du cardanol et de dérivés d'huiles végétales. Le champ d’application des polymères étant large, nous avons choisi de nous centrer sur trois grandes problématiques.Dans un premier temps, nous nous sommes intéressés à la plastification du PVC qui, actuellement, est majoritairement réalisée par des phtalates, famille d’esters pétro-sourcés vivement suspectés d’être des perturbateurs endocriniens. Des additifs de substitution ont ainsi été synthétisés par une chimie simple à partir du cardanol et d’esters gras. Des stabilités thermiques et des propriétés plastifiantes très satisfaisantes ont été obtenues. Enfin, des tests de toxicité et d’écotoxicité ont démontré l’absence d'impact perturbateur sur la sécrétion d'hormones sexuelles et la non toxicité vis-à-vis de l'environnement de ces plastifiants bio-sourcés.Dans un second temps, nous avons revisité la chimie des résines phénoplastes habituellement préparées à partir du phénol et du formaldéhyde, deux molécules classées CMR. Nous avons adapté cette chimie robuste à un phénol bio-sourcé, le cardanol, et à un aldéhyde bio-sourcé, le nonanal, pour obtenir des résines phénoliques souples. Cette propriété recherchée est le résultat d’une plastification interne des chaines lipidiques pendantes au sein du réseau polymère. Par cet exemple, l’intérêt des dérivés d’huiles végétales pour l’élaboration de matériaux souples a été démontré. Un compromis entre la souplesse des résines phénoliques et leurs résistances chimique et thermique a été atteint.Enfin, nous nous sommes tournés vers l’élaboration de polyuréthanes réticulés à partir d’un ester gras, d’un diester gras et d’un triglycéride porteurs de fonctions alpha-hydroxycétone (collaboration avec l’équipe CASYEN de l’ICBMS). L’apport de la fonction alpha-cétone sur la réactivité du polyol vis-à-vis du réactif isocyanate n’est que modeste par rapport à des dérivés présentant un groupement alcool isolé sur la chaine (huile de ricin) et alcool associé à une autre fonction alcool (triglycéride 1,2-diol). Néanmoins, la présence d’interactions intramoléculaires provenant des groupements cétone a permis d’exacerber la stabilité thermique des matériaux PU et d’élaborer des PU réticulés souples par plastification interne comme dans le cas des résines phénoliques.Cette thèse a ainsi démontré l’apport des phénols lipidiques tels que le cardanol et des chaines grasses dans l’amélioration de la stabilité thermique et de la souplesse au sein de matériaux polymères. / One of the major challenges in the field of polymers is the substitution of oil-based molecules for the development of monomers, polymers and polymer additives. The topic of this thesis is focused on the valorization of bio-sourced molecules and particularly, cardanol and vegetable oil derivatives. Since the scope of polymers is broad, we have chosen to focus on the following three major issues.At first, we were interested in the plasticization of PVC, which is most often carried out by phthalates, a family of oil-based esters strongly suspected to be endocrine disruptors. Alternative additives were thus synthesized by simple chemical reactions from cardanol and fatty esters. Good thermal stabilities and satisfactory plasticizing properties were obtained. Finally, toxicity and ecotoxicity tests have demonstrated the absence of a disruptive impact on the secretion of sex hormones and the non-toxicity towards the environment of these bio-sourced plasticizers.In a second step, we were interested in the chemistry of phenolic resins usually prepared from phenol and formaldehyde, two molecules classified as CMR substances. Thus, a bio-sourced phenol, cardanol, and a bio-sourced aldehyde, nonanal, were reacted to reach flexible phenolic resins. This peculiar property is the result of internal plasticization of the pendant lipid chains within the polymer network. By this example, the interest of vegetable oil derivatives for the production of flexible materials was demonstrated. Finally, a compromise between the flexibility of phenolic resins and their chemical and thermal resistances was reached.Finally, we turned to the development of crosslinked polyurethanes from a fatty ester, a fatty diester and a triglyceride exhibiting alpha-hydroxyketone functions (collaboration with the CASYEN team of the ICBMS). The contribution of the alpha-ketone function on the reactivity of the related to the isocyanate reagent is only modest compared to isolated alcohol type derivatives (castor oil) and alcohol associated with another alcohol function ( triglyceride 1,2-diol). Nevertheless, the presence of intramolecular interactions from ketone groups made possible to enhance the thermal stability of the PU materials and to develop flexible crosslinked PUs by internal plasticization, as in the case of phenolic resins.This thesis brings out the advantages provided by the use of lipid phenols such as cardanol and fatty chains for the improvement of thermal stability and flexibility of polymer materials.
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NanobiocompÃsitos superparamagnÃticos para aplicaÃÃo como antenas ressoadoras dielÃtricas / Superparamagnetic nanobiocomposites for application as dielectric resonator antennas

Andrà Leandro da Silva 14 August 2014 (has links)
nÃo hà / à crescente o interesse mundial pelo desenvolvimento de tecnologias chamadas âverdesâ que possibilitem o uso de produtos com menor impacto ao meio ambiente, assim como tambÃm se fortalecem as polÃticas de incentivo ao aproveitamento mÃximo e sustentÃvel dos recursos naturais. O principal objetivo desse estudo foi desenvolver nanobiocompÃsitos superparamagnÃticos para aplicaÃÃo como antenas ressoadoras dielÃtricas. Para tal, um plÃstico termorrÃgido biobaseado foi preparado utilizando o cardanol em alternativa aos fenÃis petroquÃmicos. Esse plÃstico termorrÃgido foi utilizado como matriz para o preparo de biocompÃsitos, utilizando 15% em massa de fibra de bucha bruta e tambÃm modificada por tratamento quÃmico (NaOH 5, 10 e 15% e NaClO 1%) como fase dispersa. Para o preparo dos nanobiocompÃsitos, alÃm da fibra de bucha, nanopartÃculas de magnetita, sintetizadas pelo mÃtodo da coprecipitaÃÃo, foram impregnadas no plÃstico termorrÃgido em diferentes teores de 1, 5 e 10% em massa. TÃcnicas de Termogravimetria (TG), Calorimetria exploratÃria diferencial (DSC), AnÃlise dinÃmico-mecÃnica (DMA), Microscopia eletrÃnica de varredura (MEV), Microscopia Ãptica, Microscopia eletrÃnica de transmissÃo (MET), DifraÃÃo de raios X (DRX), Espectroscopia no infravermelho com transformada de Fourier (FTIR), Espectroscopia MÃssbauer, Ensaios de resistÃncia à traÃÃo, Medidas dielÃtricas, Magnetometria de amostra vibrante (VSM) e BiodegradaÃÃo em solo simulado foram utilizadas para caracterizaÃÃo. Os resultados mostraram que o tratamento alcalino melhorou a estabilidade tÃrmica e o Ãndice de cristalinidade da fibra de bucha. O agente reticulador utilizado (DETA) mostrou-se eficiente, possibilitando a cura completa dos materiais. Os biocompÃsitos com fibra tratada apresentaram maior estabilidade tÃrmica, resistÃncia à traÃÃo superior e melhor Ãndice de biodegradaÃÃo em relaÃÃo ao biocompÃsito com fibra natural. A magnetita sintetizada exibiu tamanho nanomÃtrico, alÃm de alta pureza, alta cristalinidade e carÃter superparamagnÃtico. Todos os nanobiocompÃsitos exibiram superparamagnetismo e mostraram excelente estabilidade tÃrmica, boas taxas de biodegradaÃÃo e melhor resistÃncia mecÃnica para o material com 10% de magnetita. Todas as antenas ressoadoras dielÃtricas preparadas apresentaram perda de retorno satisfatÃria e, portanto, adequaÃÃo para fins comerciais e tecnolÃgicos, com maior potencial para atuaÃÃo em banda larga. / There is a growing global interest for the development of green technologies that allow the use of products with less damage to environment, as well as for maximum and sustainable use of natural resources. The main aim of this study was to develop superparamagnetic nanobiocomposites for application as dielectric resonator antennas. For this purpose, a biobased thermoset plastic was prepared by using cardanol as an alternative to petrochemical phenol. This thermoset plastic was used as a polymer matrix and biocomposites were prepared by using 15 wt% of untreated and modified sponge gourd fibers by chemical treatment (NaOH 5, 10, and 15 wt% and NaClO 1 wt%) as dispersed phase. For the nanobiocomposites preparation, besides the sponge gourd fibers insertion, the thermoset plastic were also impregnated with magnetite nanoparticles in different contents (1, 5, and 10 wt%). Techniques of Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), Optical Microscopy, Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), MÃssbauer Spectroscopy, Tensile testing, Dielectric measurements, Vibrating Sample Magnetometry (VSM) and Biodegradation in simulated soil were performed for characterization. The results showed that alkaline treatment improved the thermal stability and the crystallinity index of the sponge gourd fiber. The crosslinking agent used (Diethylenetriamine) was efficient and enabled complete cure for all materials. The biocomposites reinforced by treated fiber showed better thermal stability, superior performance in Tensile testing and greater biodegradation rates, when compared to the biocomposite reinforced by raw fiber. The magnetite particles exhibited nanometric size, high purity and crystallinity, and superparamagnetic character. All nanobiocomposites showed superparamagnetic behavior, excellent thermal stability, good biodegradation rates, and better mechanical strength for the material with magnetite 10 wt%. All dielectric resonators antennas exhibited satisfactory return loss and suitability for commercial and technological applications, especially for performance in broadband.

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