This thesis describes Further studies on the utilisation of the diterpenoid natural product , 12-hydrxypodocarpa-8,11,13-trim 19-oic acid* (podocarpic acid) (1) . In particular it describes transformations of the C-ring to give suitable intermediates for the synthesis of optically active steroids and terpenoids. An investigation has been carried out on the Birch reduction of 12-methoxypodocarpa-8,11,13-trien-19-ol (8), and conditions for the optimum formation of the ketonic products (10) and (12) are suggested. The enones (25) and (26) have been synthesised from 12-hydroxypodocarpa-8,11,13-trien-19-oic acid (1) by sequences involving reduction of the aromatic ring followed by ring C transformations. Methyl 12-hydroxypodocarpa-8,11,13-trien-19-oate (3) has been converted in ca. 60% yield to the dextrorotatory C 13 methyl ether which has then been reduced in good yield to the enone (163). Potential routes for conversion of the enones (25), (26), and (163)into steroidal analogues are described. Initial steps in the transformation of the C 13 methyl ether(62) into an intermediate (176) suitable for the synthesis of (+)-a-onocerin (80) have been investigated. A preliminary study on the synthesis of the C 14 phenol (190) or its methyl ether (191) is also reported. * The numbering system used throughout this thesis is that proposed by J.W. Rowe (personal communication to Professor R. C. Cambie) in "The Common and Systematic Nomenclature of Cyclic Diterpenes", 3rd Revision, Oct. 1966, to be submitted to the IUPAC Commission on Organic Nomenclature (see page 144)

This thesis describes Further studies on the utilisation of the diterpenoid natural product , 12-hydrxypodocarpa-8,11,13-trim 19-oic acid* (podocarpic acid) (1) . In particular it describes transformations of the C-ring to give suitable intermediates for the synthesis of optically active steroids and terpenoids. An investigation has been carried out on the Birch reduction of 12-methoxypodocarpa-8,11,13-trien-19-ol (8), and conditions for the optimum formation of the ketonic products (10) and (12) are suggested. The enones (25) and (26) have been synthesised from 12-hydroxypodocarpa-8,11,13-trien-19-oic acid (1) by sequences involving reduction of the aromatic ring followed by ring C transformations. Methyl 12-hydroxypodocarpa-8,11,13-trien-19-oate (3) has been converted in ca. 60% yield to the dextrorotatory C 13 methyl ether which has then been reduced in good yield to the enone (163). Potential routes for conversion of the enones (25), (26), and (163)into steroidal analogues are described. Initial steps in the transformation of the C 13 methyl ether(62) into an intermediate (176) suitable for the synthesis of (+)-a-onocerin (80) have been investigated. A preliminary study on the synthesis of the C 14 phenol (190) or its methyl ether (191) is also reported. * The numbering system used throughout this thesis is that proposed by J.W. Rowe (personal communication to Professor R. C. Cambie) in "The Common and Systematic Nomenclature of Cyclic Diterpenes", 3rd Revision, Oct. 1966, to be submitted to the IUPAC Commission on Organic Nomenclature (see page 144)

This thesis describes Further studies on the utilisation of the diterpenoid natural product , 12-hydrxypodocarpa-8,11,13-trim 19-oic acid* (podocarpic acid) (1) . In particular it describes transformations of the C-ring to give suitable intermediates for the synthesis of optically active steroids and terpenoids. An investigation has been carried out on the Birch reduction of 12-methoxypodocarpa-8,11,13-trien-19-ol (8), and conditions for the optimum formation of the ketonic products (10) and (12) are suggested. The enones (25) and (26) have been synthesised from 12-hydroxypodocarpa-8,11,13-trien-19-oic acid (1) by sequences involving reduction of the aromatic ring followed by ring C transformations. Methyl 12-hydroxypodocarpa-8,11,13-trien-19-oate (3) has been converted in ca. 60% yield to the dextrorotatory C 13 methyl ether which has then been reduced in good yield to the enone (163). Potential routes for conversion of the enones (25), (26), and (163)into steroidal analogues are described. Initial steps in the transformation of the C 13 methyl ether(62) into an intermediate (176) suitable for the synthesis of (+)-a-onocerin (80) have been investigated. A preliminary study on the synthesis of the C 14 phenol (190) or its methyl ether (191) is also reported. * The numbering system used throughout this thesis is that proposed by J.W. Rowe (personal communication to Professor R. C. Cambie) in "The Common and Systematic Nomenclature of Cyclic Diterpenes", 3rd Revision, Oct. 1966, to be submitted to the IUPAC Commission on Organic Nomenclature (see page 144)

This thesis describes Further studies on the utilisation of the diterpenoid natural product , 12-hydrxypodocarpa-8,11,13-trim 19-oic acid* (podocarpic acid) (1) . In particular it describes transformations of the C-ring to give suitable intermediates for the synthesis of optically active steroids and terpenoids. An investigation has been carried out on the Birch reduction of 12-methoxypodocarpa-8,11,13-trien-19-ol (8), and conditions for the optimum formation of the ketonic products (10) and (12) are suggested. The enones (25) and (26) have been synthesised from 12-hydroxypodocarpa-8,11,13-trien-19-oic acid (1) by sequences involving reduction of the aromatic ring followed by ring C transformations. Methyl 12-hydroxypodocarpa-8,11,13-trien-19-oate (3) has been converted in ca. 60% yield to the dextrorotatory C 13 methyl ether which has then been reduced in good yield to the enone (163). Potential routes for conversion of the enones (25), (26), and (163)into steroidal analogues are described. Initial steps in the transformation of the C 13 methyl ether(62) into an intermediate (176) suitable for the synthesis of (+)-a-onocerin (80) have been investigated. A preliminary study on the synthesis of the C 14 phenol (190) or its methyl ether (191) is also reported. * The numbering system used throughout this thesis is that proposed by J.W. Rowe (personal communication to Professor R. C. Cambie) in "The Common and Systematic Nomenclature of Cyclic Diterpenes", 3rd Revision, Oct. 1966, to be submitted to the IUPAC Commission on Organic Nomenclature (see page 144)

Orientador: Paulo Noronha Lisboa Filho / Banca: Paulo Sergio Pizani / Banca: Americo Sheitiro Tabata / O programa de Pós graduação em Ciência e Tecnologia de Materiais, POSMAT, tem carater institucional e integra as atividades de pesquisa em materiais de diversos campi da UNESP / Resumo: Há cerca de 20 anos foi descoberto o efeito magnetoresitivo em multicamadas magnéticas. Desde então, a spintrônica evoluiu de um fenômeno científico complexo para tornar-se uma tecnologia multibilionária. Dentre os parâmetros necessários para o desenvolvimento da spintrônica - a nova eletrônica que se baseia na manipulação não somente da carga, mas também do spin dos portadores -, está o controle eficiente da injeção e a detecção de portadores polarizados em spin, através de uma interface ferromagneto/semicondutor (isolante) - FM/SC(I). A utilização de semicondutores magnéticos diluídos (SMD), como ferromagnetos polarizadores de corrente, é uma solução possível para melhorar a eficiência na injeção de correntes de spins. A despeito do bom desempenho obtido com os SMDs funcionais desenvolvidos até hoje, sua baixa temperatura crítica impossibilita a utilização em temperatura ambiente. Atualmente, o progresso no campio da spintrônica depende fortemente do desenvolvimento de novos SMDs, nos quais as informações de carga e spin passam se manipuladas externamente em altas temperaturas. Em especial, é possível o desenvolvimento de semicondutores magnéticos diluídos que sejam transparentes, aumentando em muito seu potencial de aplicação em dispositivos magneto-ópticos, o que os torna naturalmente muito mais interessantes do que eletrodos ferromagneticos metálicos. A presente proposta se enquadra no plano de ampliação das linhas de atuação do grupo que inclui a implementação de técnicas sonoquímicas de síntese de materiais nanoestruturados, com potenciais aplicações em spintrônica. A mesma está baseada na preparação de amostras nanoscópicas de ZnO e TiO2 dopadas com Co²+, preparadas por irradiação ultrassônica e que terão sua estrutura investigada pelas técnicas de difração de Raios X (DRX) e microscopias eletrônicas (MEV e MET)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The phenomenon of magnetoresistive effect was discovered about twenty years ago in magnetic multilayers and opened a new field in physics, the so called spintronics, which is based on the manipulation of not only charge but also the spin of the carriers. Also, the efficient control of injection and detection of spin polarized carriers through an interface ferromagnetic/semiconductor insulator plays a role. Since then, the field of spintronics-based devices changed from an only complex scientific problem to become a multibillionaire technological issue. The use of diluted magnetic semiconductors (DMS) as current polarizers ferromagnets is one possible solution to the improvement of efficiency in the injection of spin currents. Despiste the good performance obtained with the functional DMS, their low critical temperature makes impossible the use of such devices at room temperature. Currently, progress in the field of spintronics depends heavily on the development of new DMSs, in which the charge and spin information can be manipulated at higher temperatures. In particular, it is possible the development of diluted magnetic semiconductors that are transparent; highly increasing potential application of these materials in magneto-optical devices, making them more interesting than ferromagnetic metalic electrodes. This work fits into the expansion plan of action lines of our group that includes the implementation of sonochemical technics of nanostructured materials with potential applications in spintronics, based on the preparation of nanometric size samples of Co²+ - doped ZnO and TiO2. prepared by ultrasonic irradiation. Structural characterization was performed by X-ray diffraction analyses (XRD) associated to Rietveld Refinement and electronic microscopy techniques (SEM and TEM). The optical characterization was done by UV-Vis mesurements between 200 and 800 nm and evaluating... (Complete abstract click electronic access below) / Mestre

O objetivo deste estudo foi sintetizar e caracterizar monômeros metacrilamidas, desenvolver, caracterizar e avaliar as propriedades de sistemas adesivo convencional de três passos. Foram sintetizadas bis(metacrilamida)s e tris(metacrilamida) e caracterizadas por espectroscopia de Infravermelho por Transformada de Fourier (FTIR), Ressonância Magnética Nuclear (RMN) de 1H e 13C, por Cromatografia Líquida de Alta Eficiência com Espectrometria de Massas (UHPLC-QTOF-MS) e Calorimetria Exploratória Diferencial Modulada (MDSC). Quatro bis(metacrilamidas), (1) N,N’-(propane-1,3-diyl)bis(N-ethyl-2-methylacrylamide), (2) N,N’-(octane-1,8-diyl)bis(2-methylacrylamide), (3) N,N’-(butane-1,4-diyl)bis(2-methacrylamide) e (4) N,N’-(1,4 phenylene)bis(2-methylacrylamide)monômero (1), (2), (3) e (4), e uma tris(metacrilamida) TMA, foram sintetizadas. Pela análise de FTIR-ATR foram observadas as bandas correspondentes ao estiramento do grupo C=O (1660 cm-1), C=C (1610 cm-1), N-H (3300 cm-1) e C-N (1520 cm-1). As análises de RMN identificaram a presença das ligações duplas referentes aos grupos metacrilamidas em deslocamentos químicos entre 5,3 e 5,8 ppm para 1H e entre 120 e 140 ppm para 13C.Os valores de massa exata m/z foram: 267,2068, 281,2222, 225,1595, 245,1283 e 351,2385 g/mol para os monômeros (1), (2), (3), (4) e TMA, respectivamente. A cinética de polimerização do TMA e dos adesivos experimentais contendo 2-hidroxietil acrilamida (HEAA) ou 2-hidroxietil metacrilato (HEMA) com as seguintes formulações foram investigadas por meio de DSC-PCA, n=3: TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%, TMA50%/HEMA50%, BisGMA/HEAA/TMA e BisGMA/HEMA.Características e propriedades mecânicas das resinas adesivas BisGMA/HEAA/TMA e BisGMA/HEMA foram avaliadas por resistência coesiva (UTS, n=5), degradação em solvente (ΔKHN, n=5), ângulo de contato (n=5), microtração (μTBS, n=20) e análise de fratura. Um primer a base de acrilamidas foi desenvolvido (H2O/HEAA/AMPS) (2-acrylamida-2-methilpropano ácido sulfônico) para ser utilizado no grupo experimental com metacrilamidas. Os valores de pH e ângulo de contato do primer experimental foram comparados com o primer do ScotchBond Multi-purpose (grupo controle). O monômero (1) resultou em um monômero amarelo claro de baixa viscosidade, entretanto, não apresentou foto ou termopolimerização. A energia de ativação determinada pelo método de Kissinger foi – 165,8 kJmol-1; -182,7 kJmol-1 e -156,7 kJmol-1 para os monômeros (2), (3) e (4), respectivamente. Sistemas adesivos convencionais de três passos a base de metacrilamidas e a base de metacrilatos foram desenvolvidos. Resinas adesivas contendo somente HEAA e TMA (TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%) apresentaram grau de conversão abaixo de 40% após 40 s de fotoativação. Alto grau de conversão (acima de 60%) só foi encontrado para as resinas adesivas BisGMA/HEAA/TMA e BisGMA/HEMA e sem diferença significativa entre elas, p>0,05. Os valores de UTS (BisGMA/HEMA- 67,7 ±5 MPa e BisGMA/HEAA/TMA- 60,5 ±7 MPa), μTBS (BisGMA/HEMA- 57 ± 14 MPa e BisGMA/HEAA/TMA- 53,1 ±15 MPa) e ângulo de contato (BisGMA/HEMA- 39,5 ±9 e BisGMA/HEAA/TMA- 46,7 ±15) não apresentaram diferença estatística, p>0.05. O primer experimental apresentou um valor pH mais baixo (2,7) bem como de ângulo de contato (18,5 ±5) em relação ao comercial (pH-4 e θ-33,5 ±4). A síntese proposta para os monômeros (1), (2), (3), (4) e TMA foi caracterizada nesse trabalho. Um primer somente com acrilamidas foi desenvolvido e a presença do novo monômero TMA na resina adesiva BisGMA/HEAA permitiu a formulação de um sistema adesivo convencional de três passos sem a presença do monômero HEMA. / The aim of this study was synthesized and characterizes methacrylamides monomers, development, characterizer and evaluated the properties of 3-step etch-and-rise adhesive system. Bis(methacrylamide)s and tris(methacrylamide) were synthesized. The monomer structures were confirmed by 1H and 13C Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR-ATR), Ultra-high liquid chromatography quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS) and modulated differential scanning calorimetry (mDSC). Four bis(methacrylamide)s monomers (1) N,N’-(propane-1,3-diyl)bis(N-ethyl-2-methylacrylamide), (2) N,N’-(octane-1,8-diyl)bis(2-methylacrylamide), (3) N,N’-(butane-1,4-diyl)bis(2-methacrylamide) and (4) N,N’-(1,4 phenylene)bis(2-methylacrylamide) and one tris(methacrylamide), TMA, were synthesized. All IR spectra of the monomers showed the C=C axial deformation at 1610 cm-1. The 1H NMR spectra the olefinic hydrogens were observed at 5.3 an 5.8 ppm and in the 13C NMR, the vinylic carbons at 120 and 140 ppm. The exact m/z values were: 267.2068, 281.2222, 225.1595, 245.1283 and 351.2385 g/mol for monomers (1), (2), (3), (4) and TMA respectively. Monomer (1) not presented photo (DSC-PCA) or thermal polymerization. The activation energy determined using Kissinger methodology was: - 165.8 kJmol-1; -182.7 kJmol-1 and -156.7 kJmol-1 for monomers (2), (3) and (4), respectively. 3-step adhesive systems with methacrylamides and methcrylates were development. Kinetics of photopolymerization of TMA and experimental adhesive resin containing 2-hydroxyethylacrylamide (HEAA) or 2-hydroxyethylmethacrylate (HEMA) in the following formulations: (TMA 33%/HEAA 66%, TMA 50%/HEAA 50%, TMA66%/HEAA33%, TMA50%/HEMA50%, BisGMA66%/HEAA24%/TMA10% and BisGMA66%/HEMA33%) were investigated through DSC-PCA. Characteristics and mechanical properties for BisGMA 66%/HEAA 24%/TMA 10% and BisGMA 66%/HEMA 33% adhesives were evaluated with ultimate tensile strength (UTS, n=5), softening in solvent (ΔKHN, n=5), contact angle (n=5), microtensile bond strength (μTBS, n=20) and failure analysis. A primer was also formulated with H2O/HEAA/AMPS (2-acrylamido-2-methylpropane sulfonic acid) and the pH and contact angle value were verified and compared to commercial ScotchBond primer. Adhesive resin with HEAA and TMA (TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%) showed lower conversion and polymerization rate after 40 s of light activation. Higher conversion (up to 60%) was found for BisGMA/HEAA/TMA and BisGMA/HEMA adhesive resin without significant difference between adhesive resin, p>0.05. UTS (BisGMA/HEMA- 67.7 ±5 MPa e BisGMA/HEAA/TMA- 60.5 ±7 MPa), immediate μTBS (BisGMA/HEMA- 57 ± 14 MPa e BisGMA/HEAA/TMA- 53.1 ±15 MPa), ΔKHN (BisGMA/HEMA- 56 ± 7 e BisGMA/HEAA/TMA- 64 ±4) and contact angle (BisGMA/HEMA- 39.5 ±9 e BisGMA/HEAA/TMA- 46.7 ±15) showed no statistical difference, p>0.05. The experimental primer presented more acidity pH (2.7) and lower contact angle (18.5 ±5) when compared to commercial primer (pH- 4 e θ- 33.5 ±4). A new acrylamide based-primer was formulated and the presence of the new tris(methacrylamide) monomer (TMA) was enable the preparation of a 3-step etch-and-rise adhesive system without HEMA monomer.

Submitted by RAFAEL APARECIDO FERREIRA null (frafael@fc.unesp.br) on 2016-10-26T23:30:15Z No. of bitstreams: 1 TESE_VERSAOFINAL_RAFAELFERREIRA_20102016.pdf: 3557281 bytes, checksum: 8e435622b72935c72d8a57048fe6b882 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-11-01T15:32:14Z (GMT) No. of bitstreams: 1 ferreira_ra_dr_bauru.pdf: 3557281 bytes, checksum: 8e435622b72935c72d8a57048fe6b882 (MD5) / Made available in DSpace on 2016-11-01T15:32:14Z (GMT). No. of bitstreams: 1 ferreira_ra_dr_bauru.pdf: 3557281 bytes, checksum: 8e435622b72935c72d8a57048fe6b882 (MD5) Previous issue date: 2016-08-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve como objetivo otimizar rotas de síntese de diferentes métodos de materiais cerâmicos monofásicos e estudar propriedades cristalográficas e magnéticas de manganitas destes materiais. Foram utilizados os métodos da reação no estado sólido, método da reação de combustão e o método hidrotérmico. Após otimização, foram sintetizadas pelo método da reação de combustão amostras com composição nominal Bi1-xMxMn2O5, onde (M= Eu, Er e x = 0,10). Para obter as fases desejadas, os materiais sintetizados pelo método da combustão foram tratados termicamente a diferentes temperaturas de 600°C, 700°C e 800°C para amostras de composição BiMn2O5, e a 900°C para as amostras com substituições de Eu e Er. Já, as amostras obtidas pelo método da reação no estado sólido foram tratadas a 700, 750 e 800°C por 24 horas em cada temperatura. Para o estudo da das fases cristalográficas formadas nos materiais foi utilizada a difração de raios X, seguida do refinamento estrutural pelo método de Rietveld. Os métodos de síntese, por combustão com ureia e de reação no estado sólido, permitiram obter amostras monofásicas para o material com composição nominal BiMn2O5, que apresentaram estrutura perovisquita do tipo mulita e grupo espacial Pbam, a reação de combustão com ureia permitiu também obter amostras monofásicas para a composição nominal Bi1-xMxMn2O5, na qual (M = Eu e x = 0,10), onde foi observada a formação de um material monofásico com a mesma estrutura e grupo espacial do BiMn2O5 (ICSD-026806), que sugere a substituição do sítio do Bi+3 por cátions Eu+3, para as composições nominais onde x = 0,1. A microscopia eletrônica de varredura indicou que o material sintetizado pelo método de combustão por ureia apresentou uma boa distribuição de partículas da ordem de 300 nm, enquanto que o método da reação no estado sólido permitiu obter amostras da ordem de 1 µm. No estudo do comportamento magnético das amostras foram realizadas medidas magnéticas em função da temperatura em procedimento ZFC (medida de magnetização com resfriamento sem campo magnético aplicado) e FC (medida de magnetização com resfriamento com campo magnético aplicado) na faixa de temperaturas de 2 a 300 K, para campos magnéticos aplicados de 100 Oe, para as amostras obtidas pelo método do estado sólido, que apresentaram comportamento típico antiferromagnético nas duas curvas (TN ~ 40 K). As medidas de magnetização em função da temperatura, obtidas pelo procedimento ZFC-FC, indicaram que as amostras com composição BiMn2O5, obtidas pelos métodos da reação por combustão apresentam uma resposta típica antiferromagnética com TN ~ 40 K nas curvas medidas em modo ZFC. Tal resposta se deve a ocupação dos cátions de Mn+3 nos sítios pirâmide tetragonal e Mn+4 nos sítios octaédricos da estrutura perovisquita do tipo mulita. Por fim, as amostras com composição nominal Bi0,9Eu0,1Mn2O5 apresentam um aumento na magnetização do material trazendo uma componente ferromagnética para o mesmo observada na sua curva FC com TC em 44,3 K. Isto ocorre devido a o momento magnético não nulo dos íons Eu3+, que ocupam os sítios octaedrais do bismuto. / The objective of this work is to optimize different methods of routes for synthesis of monophasic ceramic materials, and to study the crystallographic as well as its manganites magnetic properties. The reaction methods to be analyzed were the solid state reaction method, the combustion reaction method and the hidrothermic method. After optimization, the samples with nominal composition of Bi1-xMxMn2O5 (M= Eu, Er e x = 0.10) were synthesized using the combustion reaction method. With the aim of obtaining the desired phases, the synthesized materials using the combustion reaction method were then treated thermally at 600, 700 and 800oC for the samples presenting composition BiMn2O5, and 900oC for the samples containing substitutions Eu and Er. The samples obtained by the solid state reaction method were treated at 700, 750 and 800oC for 24 hours for each temperature. The X-ray diffraction using the Rietveld method for structural refining was used to study the crystallographic phases formed in the studied materials. The synthesis methods for combustion with urea as well as solid state allowed to obtain monophasic samples for the materials with nominal composition of BiMn2O5. They presented perovskite-like mullite-type structure with special group Pbam. The combustion reaction method with urea also allowed to obtain monophasic samples with nominal composition Bi1-xMxMn2O5, (M = Eu e x = 0.10), where it was possible to observe the formation of a monophasic material with the same structure and space group of BiMn2O5 (ICSD-026806). This result suggests the substitution of the Bi3+ site for Eu3+ cations for the nominal compositions with x = 0.1. The scanning electron microscopy indicated that the materials synthesized for combustion with urea presented a good particle distribution in the order of 300 nm, while the materials synthesized for solid state allowed to obtain samples in the order of 1 µm. The studies involving the magnetic behavior of the samples were performed through magnetic measurements as a function of temperature with ZFC (zero field cooled), as well as FC (field cooled). The measurements were performed in the range of temperatures from 2 to 300 K for the applied magnetic fields of 100 Oe when used samples obtained by the solid state reaction method. They presented typical antiferromagnetic behavior in the two curves (TN ~ 40 K). The measurements of magnetization as a function of temperature obtained through the ZFC-FC procedures indicated that the samples with composition BiMn2O5 obtained by the combustion reaction method presented a typical antiferromagnetic response with TN ~ 40 K in the curves measured in ZFC mode. Such a response is due to the occupation of Mn3+ cation in the tetragonal pyramid sites and Mn4+ in the octaedric sites for the perovskite structure mullite-type. Lastly, the samples with nominal composition Bi0,9Eu0,1Mn2O5 presented an increase in the material magnetization bringing a ferromagnetic component to the same observed in its FC curve with TC ~ 44,3 K. The last happens due to a not null magnetic moment of the Eu3+ ions that occupy the octaedric sites of bismuth. / CAPES: 8965/11-0

Orientador: Paulo Noronha Lisboa Filho / Banca: Marcia Tsuyama Escote / Banca: Herbert Winnishchofer / O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp / Resumo: Materiais óxidos avançados com composição nominal Ni'Mn IND. 2''O IND. 4' e Co'Mn IND. 2''O IND. 4' obtidos pelo métodos dos precursores poliméricos foram tratados termicamente em diferentes temperaturas ('800 GRAUS'C /4h e '1000 GRAUS'C/16h) com a finalidade de obter um material monofásico, condição essa ideal para o estudo das propriedades cristalográficas, estruturais e magnéticas destes compostos. A obtenção de materiais monofásicos é importante para uma melhor interpretação das suas propriedades magnéticas. o método dos precursores poliméricos permitiu obter amostras com quantidades mínimas de fases secundárias, confirmadas por difração de raios X e refinamento estrutural pelo método de Rietveld. As medidas de magnetização indicam que tanto as amostras Ni'Mn IND. 2''O IND. 4' e Co'Mn IND. 2''O IND. 4' apresentam uma competição entre duas subredes, uma com resposta ferromagnética, e outra com resposta antiferromagnética e isso deve se a ocupação dos cátions dentro dos sítios tetraédricos e octaédricos do espinélio. Para a determinação das fases do Ni'Mn IND. 2''O IND. 4' e do Co'Mn IND. 2''O IND. 4', foi utilizada a técnica de difração de raios X (DRX), a qual mostra a formação de duas fases para a composição Ni'Mn IND. 2''O IND. 4': uma fase predominante de Ni'Mn IND. 2''O IND. 4' (ICSD-9403) com estrutura cúbica do tipo espinélio e uma fase secundária de NiO (COD 9008693) arranjada em estrutura do tipo cúbica. Já a composição Co'Mn IND. 2''O IND. 4' se cristaliza como um espinélio cin sistema tetragonal (JCPDS - 77-0471) como fase principal. Para os estudos do comportamento magnético das amostras foram realizadas medidas magnéticas com procedimento ZFC-FC de 10 k a 300 com campos aplicados de 100 Oe, 500 Oe and 1 kOe. Para um campo aplicado de 100 Oe a amostra de Ni'Mn IND. 2''O IND. 4' exibe uma resposta antiferromagnética na ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Advanced oxide materials with nominal composition Ni'Mn IND. 2''O IND. 4' and Co'Mn IND. 2''O IND. 4' obtained by polymeric precursors method was heat-treated at different temperatures ('800 GRAUS'C/4h and '1000 GRAUS'C/16h) in order to obtain a single-phase material, being the ideal condition for the magnetic measurements and structural refinement by the Rietveld method to be performed. In order to obtain single-phase materials is important to better explaining the magnetic behavior of the sample. The polymeric precursor method allowed obtaining samples with minimal amounts of secundary phase, confirmed by X-ray difraction technique and structural refinement by the Rietveld method. The magnetic measurements indicate that the samples Ni'Mn IND. 2''O IND. 4' and Co'Mn IND. 2''O IND. 4' presents a competition between ferromagnetic and antiferromagnetic respondes for the different magnetic sublattice, this should be the occupation in the tethahedral and octahedral sites of spinel. For the determination of the Ni'Mn IND. 2''O IND. 4' and Co'Mn IND. 2''O IND. 4' phases, was used XRD technique, which showed the formation of two phases for the composition Ni'Mn IND. 2''O IND. 4": a predominant phase Ni'Mn IND. 2''O IND. 4' (ICSD-9403) with spinel arranged in a cubic system and a secondary phase of NiO (COD 9008693) with cubic type structure. Otherwise, the Co'Mn IND. 2''O IND. 4' composition showed the crystallization in a tetragonal system (JCPDS - 77-0471), as a main crystallographic phase. Magnetization curves were obtained as a function of the temperature in ZFC-FC procedure in magnetic fields of 100 Oe, 500 Oe and 1 KOe. For a field applied of 100 Oe the sample showed an antiferromagnetic response in the ZFC curve, while in the FC curve a ferromagnetic behavior can be observed for the Ni'Mn IND. 2''O IND. 4' composition. Magnetization curves showed ferromagnetic ... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:30:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-29Bitstream added on 2014-06-13T20:00:19Z : No. of bitstreams: 1 ferreira_ra_me_bauru.pdf: 3811229 bytes, checksum: b51793ae67a357adf80cbf853622e523 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Materiais óxidos avançados com composição nominal Ni'Mn IND. 2''O IND. 4' e Co'Mn IND. 2''O IND. 4' obtidos pelo métodos dos precursores poliméricos foram tratados termicamente em diferentes temperaturas ('800 GRAUS'C /4h e '1000 GRAUS'C/16h) com a finalidade de obter um material monofásico, condição essa ideal para o estudo das propriedades cristalográficas, estruturais e magnéticas destes compostos. A obtenção de materiais monofásicos é importante para uma melhor interpretação das suas propriedades magnéticas. o método dos precursores poliméricos permitiu obter amostras com quantidades mínimas de fases secundárias, confirmadas por difração de raios X e refinamento estrutural pelo método de Rietveld. As medidas de magnetização indicam que tanto as amostras Ni'Mn IND. 2''O IND. 4' e Co'Mn IND. 2''O IND. 4' apresentam uma competição entre duas subredes, uma com resposta ferromagnética, e outra com resposta antiferromagnética e isso deve se a ocupação dos cátions dentro dos sítios tetraédricos e octaédricos do espinélio. Para a determinação das fases do Ni'Mn IND. 2''O IND. 4' e do Co'Mn IND. 2''O IND. 4', foi utilizada a técnica de difração de raios X (DRX), a qual mostra a formação de duas fases para a composição Ni'Mn IND. 2''O IND. 4': uma fase predominante de Ni'Mn IND. 2''O IND. 4' (ICSD-9403) com estrutura cúbica do tipo espinélio e uma fase secundária de NiO (COD 9008693) arranjada em estrutura do tipo cúbica. Já a composição Co'Mn IND. 2''O IND. 4' se cristaliza como um espinélio cin sistema tetragonal (JCPDS - 77-0471) como fase principal. Para os estudos do comportamento magnético das amostras foram realizadas medidas magnéticas com procedimento ZFC-FC de 10 k a 300 com campos aplicados de 100 Oe, 500 Oe and 1 kOe. Para um campo aplicado de 100 Oe a amostra de Ni'Mn IND. 2''O IND. 4' exibe uma resposta antiferromagnética na... / Advanced oxide materials with nominal composition Ni'Mn IND. 2''O IND. 4' and Co'Mn IND. 2''O IND. 4' obtained by polymeric precursors method was heat-treated at different temperatures ('800 GRAUS'C/4h and '1000 GRAUS'C/16h) in order to obtain a single-phase material, being the ideal condition for the magnetic measurements and structural refinement by the Rietveld method to be performed. In order to obtain single-phase materials is important to better explaining the magnetic behavior of the sample. The polymeric precursor method allowed obtaining samples with minimal amounts of secundary phase, confirmed by X-ray difraction technique and structural refinement by the Rietveld method. The magnetic measurements indicate that the samples Ni'Mn IND. 2''O IND. 4' and Co'Mn IND. 2''O IND. 4' presents a competition between ferromagnetic and antiferromagnetic respondes for the different magnetic sublattice, this should be the occupation in the tethahedral and octahedral sites of spinel. For the determination of the Ni'Mn IND. 2''O IND. 4' and Co'Mn IND. 2''O IND. 4' phases, was used XRD technique, which showed the formation of two phases for the composition Ni'Mn IND. 2''O IND. 4: a predominant phase Ni'Mn IND. 2''O IND. 4' (ICSD-9403) with spinel arranged in a cubic system and a secondary phase of NiO (COD 9008693) with cubic type structure. Otherwise, the Co'Mn IND. 2''O IND. 4' composition showed the crystallization in a tetragonal system (JCPDS - 77-0471), as a main crystallographic phase. Magnetization curves were obtained as a function of the temperature in ZFC-FC procedure in magnetic fields of 100 Oe, 500 Oe and 1 KOe. For a field applied of 100 Oe the sample showed an antiferromagnetic response in the ZFC curve, while in the FC curve a ferromagnetic behavior can be observed for the Ni'Mn IND. 2''O IND. 4' composition. Magnetization curves showed ferromagnetic ... (Complete abstract click electronic access below)

O objetivo deste estudo foi sintetizar e caracterizar monômeros metacrilamidas, desenvolver, caracterizar e avaliar as propriedades de sistemas adesivo convencional de três passos. Foram sintetizadas bis(metacrilamida)s e tris(metacrilamida) e caracterizadas por espectroscopia de Infravermelho por Transformada de Fourier (FTIR), Ressonância Magnética Nuclear (RMN) de 1H e 13C, por Cromatografia Líquida de Alta Eficiência com Espectrometria de Massas (UHPLC-QTOF-MS) e Calorimetria Exploratória Diferencial Modulada (MDSC). Quatro bis(metacrilamidas), (1) N,N’-(propane-1,3-diyl)bis(N-ethyl-2-methylacrylamide), (2) N,N’-(octane-1,8-diyl)bis(2-methylacrylamide), (3) N,N’-(butane-1,4-diyl)bis(2-methacrylamide) e (4) N,N’-(1,4 phenylene)bis(2-methylacrylamide)monômero (1), (2), (3) e (4), e uma tris(metacrilamida) TMA, foram sintetizadas. Pela análise de FTIR-ATR foram observadas as bandas correspondentes ao estiramento do grupo C=O (1660 cm-1), C=C (1610 cm-1), N-H (3300 cm-1) e C-N (1520 cm-1). As análises de RMN identificaram a presença das ligações duplas referentes aos grupos metacrilamidas em deslocamentos químicos entre 5,3 e 5,8 ppm para 1H e entre 120 e 140 ppm para 13C.Os valores de massa exata m/z foram: 267,2068, 281,2222, 225,1595, 245,1283 e 351,2385 g/mol para os monômeros (1), (2), (3), (4) e TMA, respectivamente. A cinética de polimerização do TMA e dos adesivos experimentais contendo 2-hidroxietil acrilamida (HEAA) ou 2-hidroxietil metacrilato (HEMA) com as seguintes formulações foram investigadas por meio de DSC-PCA, n=3: TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%, TMA50%/HEMA50%, BisGMA/HEAA/TMA e BisGMA/HEMA.Características e propriedades mecânicas das resinas adesivas BisGMA/HEAA/TMA e BisGMA/HEMA foram avaliadas por resistência coesiva (UTS, n=5), degradação em solvente (ΔKHN, n=5), ângulo de contato (n=5), microtração (μTBS, n=20) e análise de fratura. Um primer a base de acrilamidas foi desenvolvido (H2O/HEAA/AMPS) (2-acrylamida-2-methilpropano ácido sulfônico) para ser utilizado no grupo experimental com metacrilamidas. Os valores de pH e ângulo de contato do primer experimental foram comparados com o primer do ScotchBond Multi-purpose (grupo controle). O monômero (1) resultou em um monômero amarelo claro de baixa viscosidade, entretanto, não apresentou foto ou termopolimerização. A energia de ativação determinada pelo método de Kissinger foi – 165,8 kJmol-1; -182,7 kJmol-1 e -156,7 kJmol-1 para os monômeros (2), (3) e (4), respectivamente. Sistemas adesivos convencionais de três passos a base de metacrilamidas e a base de metacrilatos foram desenvolvidos. Resinas adesivas contendo somente HEAA e TMA (TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%) apresentaram grau de conversão abaixo de 40% após 40 s de fotoativação. Alto grau de conversão (acima de 60%) só foi encontrado para as resinas adesivas BisGMA/HEAA/TMA e BisGMA/HEMA e sem diferença significativa entre elas, p>0,05. Os valores de UTS (BisGMA/HEMA- 67,7 ±5 MPa e BisGMA/HEAA/TMA- 60,5 ±7 MPa), μTBS (BisGMA/HEMA- 57 ± 14 MPa e BisGMA/HEAA/TMA- 53,1 ±15 MPa) e ângulo de contato (BisGMA/HEMA- 39,5 ±9 e BisGMA/HEAA/TMA- 46,7 ±15) não apresentaram diferença estatística, p>0.05. O primer experimental apresentou um valor pH mais baixo (2,7) bem como de ângulo de contato (18,5 ±5) em relação ao comercial (pH-4 e θ-33,5 ±4). A síntese proposta para os monômeros (1), (2), (3), (4) e TMA foi caracterizada nesse trabalho. Um primer somente com acrilamidas foi desenvolvido e a presença do novo monômero TMA na resina adesiva BisGMA/HEAA permitiu a formulação de um sistema adesivo convencional de três passos sem a presença do monômero HEMA. / The aim of this study was synthesized and characterizes methacrylamides monomers, development, characterizer and evaluated the properties of 3-step etch-and-rise adhesive system. Bis(methacrylamide)s and tris(methacrylamide) were synthesized. The monomer structures were confirmed by 1H and 13C Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR-ATR), Ultra-high liquid chromatography quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS) and modulated differential scanning calorimetry (mDSC). Four bis(methacrylamide)s monomers (1) N,N’-(propane-1,3-diyl)bis(N-ethyl-2-methylacrylamide), (2) N,N’-(octane-1,8-diyl)bis(2-methylacrylamide), (3) N,N’-(butane-1,4-diyl)bis(2-methacrylamide) and (4) N,N’-(1,4 phenylene)bis(2-methylacrylamide) and one tris(methacrylamide), TMA, were synthesized. All IR spectra of the monomers showed the C=C axial deformation at 1610 cm-1. The 1H NMR spectra the olefinic hydrogens were observed at 5.3 an 5.8 ppm and in the 13C NMR, the vinylic carbons at 120 and 140 ppm. The exact m/z values were: 267.2068, 281.2222, 225.1595, 245.1283 and 351.2385 g/mol for monomers (1), (2), (3), (4) and TMA respectively. Monomer (1) not presented photo (DSC-PCA) or thermal polymerization. The activation energy determined using Kissinger methodology was: - 165.8 kJmol-1; -182.7 kJmol-1 and -156.7 kJmol-1 for monomers (2), (3) and (4), respectively. 3-step adhesive systems with methacrylamides and methcrylates were development. Kinetics of photopolymerization of TMA and experimental adhesive resin containing 2-hydroxyethylacrylamide (HEAA) or 2-hydroxyethylmethacrylate (HEMA) in the following formulations: (TMA 33%/HEAA 66%, TMA 50%/HEAA 50%, TMA66%/HEAA33%, TMA50%/HEMA50%, BisGMA66%/HEAA24%/TMA10% and BisGMA66%/HEMA33%) were investigated through DSC-PCA. Characteristics and mechanical properties for BisGMA 66%/HEAA 24%/TMA 10% and BisGMA 66%/HEMA 33% adhesives were evaluated with ultimate tensile strength (UTS, n=5), softening in solvent (ΔKHN, n=5), contact angle (n=5), microtensile bond strength (μTBS, n=20) and failure analysis. A primer was also formulated with H2O/HEAA/AMPS (2-acrylamido-2-methylpropane sulfonic acid) and the pH and contact angle value were verified and compared to commercial ScotchBond primer. Adhesive resin with HEAA and TMA (TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%) showed lower conversion and polymerization rate after 40 s of light activation. Higher conversion (up to 60%) was found for BisGMA/HEAA/TMA and BisGMA/HEMA adhesive resin without significant difference between adhesive resin, p>0.05. UTS (BisGMA/HEMA- 67.7 ±5 MPa e BisGMA/HEAA/TMA- 60.5 ±7 MPa), immediate μTBS (BisGMA/HEMA- 57 ± 14 MPa e BisGMA/HEAA/TMA- 53.1 ±15 MPa), ΔKHN (BisGMA/HEMA- 56 ± 7 e BisGMA/HEAA/TMA- 64 ±4) and contact angle (BisGMA/HEMA- 39.5 ±9 e BisGMA/HEAA/TMA- 46.7 ±15) showed no statistical difference, p>0.05. The experimental primer presented more acidity pH (2.7) and lower contact angle (18.5 ±5) when compared to commercial primer (pH- 4 e θ- 33.5 ±4). A new acrylamide based-primer was formulated and the presence of the new tris(methacrylamide) monomer (TMA) was enable the preparation of a 3-step etch-and-rise adhesive system without HEMA monomer.