Orientador: Maria Isabel Felisberti / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-17T08:46:35Z (GMT). No. of bitstreams: 1 Santos_LuisEduardoPaisdos_D.pdf: 4191396 bytes, checksum: d2ee438006096211a78208eaecc89877 (MD5) Previous issue date: 2010 / Resumo: Este trabalho objetivou a síntese de copolímeros contendo grupos iônicos. Foram utilizadas diferentes rotas sintéticas para a obtenção de copolímeros de estireno (S) e ácido vinilfosfônico (AVF) (P(S-co-AVF)): 1. Copolimerização radicalar destes monômeros; 2. Copolimerização de estireno e vinilfosfonato de dimetila (VFDM) (P(S-co-VFDM)), seguida de hidrólise. Foram variadas as composições e condições de síntese. Copolímeros P(S-co- AVF) foram obtidos por polimerização radicalar em solução de dimetilformamida, utilizando peróxido de benzoíla (BPO) como iniciador. Estes copolímeros apresentaram baixo grau de inserção de AVF, entretanto, observou-se aumento da temperatura de transição vítrea (Tg), da resistência térmica e do teor de resíduos a 900°C, assim como a diminuição da massa molar com o incremento de AVF. Copolímeros P(S-co-VFDM) foram sintetizados por polimerização em solução de tolueno e em bulk, utilizando BPO como iniciador. Os copolímeros obtidos em bulk apresentaram maior inserção de VFDM, em comparação aos copolímeros obtidos em solução, partindo-se das mesmas frações molares dos monômeros, como conseqüência do maior tempo de reação para o primeiro caso. O aumento do teor de VFDM nos copolímeros causa a diminuição da massa molar, da Tg, da resistência térmica e do aumento no teor de resíduo a 900°C. Enquanto os copolímeros obtidos em bulk apresentaram degradação térmica complexa, os copolímeros obtidos em solução apresentam basicamente despolimerização. Os parâmetros de copolimerização dos monômeros S (rS) e VFDM (rVFDM) foram determinados pelos métodos de Mayo e Lewis e de Kelen e Tüdõs, sendo o parâmetro de copolimerização consideravelmente maior para o estireno (rS/rVFDM ~ 30). Os copolímeros obtidos em bulk foram hidrolisados em meio alcalino, obtendo-se ionômeros e polieletrólitos. Apesar da hidrólise não ser completa, a presença de grupos iônicos nestes copolímeros aumenta a Tg, o teor de resíduos e a complexidade da degradação térmica. / Abstract: The main purpose of this work was to synthesize copolymers with ionic groups. Different synthetic routes were applied to obtain copolymers of styrene (S) and vinylphosphonic acid (AVF) (P(S-co-AVF)): 1. Radical copolymerization of these monomers; and 2. Copolymerization of styrene and dimethyl-vinylphosphonate (VFDM) (P(S-co-VFDM)), followed by hydrolysis. The P(S-co-AVF) copolymers were obtained by radical polymerization in dimethylformamide solution using benzoyl peroxide (BPO) as an initiator. These copolymers presented low AVF insertion level. However, increase of the glass transition temperature (Tg), thermal resistance and residue at 900°C were observed. Besides, a decrease of the molar mass was observed with the increase of AVF content. P(S-co-VFDM) copolymers were synthesized by polymerization in toluene solution and in bulk, using also BPO as the initiator. The copolymers obtained by bulk polymerization presented higher VFDM insertion level than the copolymers obtained in solution, considering the same monomers molar fractions in the reactional medium. This behavior was a consequence of the higher reaction time involved in the first method. The increase of the VFDM content in the copolymers caused decreases of the molar mass, of the Tg and of the thermal resistance, and an increase of the residues level at 900°C. Moreover, the copolymers obtained in bulk presented a complex thermal degradation mechanism, while the copolymers obtained in solution presented basically a depolymerization. The copolymerization parameters of the monomers S (rS) and VFDM (rVFDM) were determined by Mayo and Lewis method and by Kelen and Tüdõs method. The copolymerization parameter of the styrene was significantly higher than the parameter of the (rS/rVFDM ~ 30). The copolymers obtained in bulk were hydrolyzed in an alkaline medium, resulting in ionomers and polyelectrolytes. Even though the hydrolysis was incomplete, the presence of the ionic groups in these copolymers has altered significantly its solubility and thermal degradation mechanism and has increased its Tg and residue level. / Doutorado / Físico-Química / Doutor em Ciências

The copolymerization of the monomers 3,3’” Dihexyl-2,2’:5’,2″:5″,2’″-quaterthiophene (DQT) and (R)-(-)-3-(1-pyrrolyl)propyl-N-(3,5-dinitrobenzoyl)-α-phenylglycinate (DNBP), as well as the 2,2′:5′,2′′-terthiophene (TTF) and DNBP was successfully achieved by electrochemical techniques. Poly(DQT), poly(TTF), poly(DNBP), poly(DQT-co-DNBP) and poly(TTF-co-DNBP) films were characterized by infrared spectroscopy, Scanning Electron Microscopy (SEM), spectroelectrochemical and fluorescence spectroscopy techniques. The infrared spectroscopy confirmed the presence of the main functional groups of the homopolymers. The two copolymers obtained in feed ratio showed morphologies their precursor polymers. It was observed, for all copolymers reversible changes in the color of the films during the electrochemical characterization by cyclic voltammetry, the films of poly(DQT-co-DNBP) showed changes from yellow or orange in the reduced state to green or blue in the state oxidized, but this dependent on the proportion of the comonomers. All films of poly(TTF-co-DNBP) exhibited color changes from orange to brown in the reduced state in the oxidized state. These changes are more significant in the films of poly(DQT-co-DNBP) deposited with 1:5 feed ratio and poly(TTF-co-DNBP) deposited with 1:8 feed ratio, as shown by the track of the CIE 1931 xy chromaticity coordinates and by the electrochromic parameters. The films of poly(DQT-co-DNBP) in the ratio 1:5 (thickness 0.8 ± 0.2 µm) presented chromatic contrast (ΔT%) at 660 nm of 62 %, coulombic efficiency of 48 %, electrochromic efficiency (η) ~ 230 C cm-2 and redox stability (ΔT% = 17% in λ = 660 nm at the 1000th cycle). While the films of poly(TTF-co-DNBP) in the ratio 1: 8 (thickness 1.0 ± 0.2 µm) presented a coulombic efficiency of approximately 81 %, chromatic contrast on the order of 48 % in λ = 1065 nm and coloration efficiency in the range of 180 C cm-2 with good stability up to 700 cycles of charging / discharging. Solutions of poly(DQT) and poly(TTF) its copolymers with DNBP (independently of the feed ratio) in N-methylpyrrolidone (NMP) are fluorescente. The copolymers of poly(DQT-co-DNBP) have emission bands at 555 and 585 nm when excited at 375 nm and copolymers of poly(TTF-co-DNBP) emit at 516 and 548 nm when excited at 450 nm. Therefore, these polymers are promising as materials having fluorescent and electrochromic properties and may be applied as an active layer for optoelectronic devices such as OLEDs and electrochromic devices. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A copolimerização dos monômeros 3,3”’-Diexil-2,2’:5’,2”:5”,2”’-quatertiofeno (DQT) e (R)-(-)-N-(3,5-dinitrobenzoil)-α-fenilglicinato de 1-(3-pirrolil)propila (DNBP), como também do 2,2’:5’,2”-tertiofeno (TTF) e o DNBP foi realizada com sucesso, através de técnicas eletroquímicas. Os copolímeros obtidos apresentaram propriedades otimizadas em comparação com os filmes dos polímeros precursores poli(DQT), poli(TTF) e poli(DNBP). Os filmes de poli(DQT), poli(TTF), poli(DNBP), poli(DQT-co-DNBP) e poli(TTF-co-DNBP) foram caracterizados através das técnicas de espectroscopia de infravermelho (FTIR), microscopia eletrônica de varredura (MEV), espectroeletroquímica e espectroscopia de fluorescência. A espectroscopia de infravermelho confirmou a presença dos principais grupos funcionais dos homopolímeros nos copolímeros formados. Os dois copolímeros obtidos, em diferentes proporções, apresentaram morfologias intermediárias aos seus polímeros precursores. Foram observadas mudanças reversíveis na coloração dos filmes durante a caracterização eletroquímica por voltametria cíclica em todos os copolímeros, onde os filmes de poli(DQT-co-DNBP) apresentaram uma mudança de coloração de amarelo ou alaranjado no estado reduzido para verde ou azul no estado oxidado, dependendo da proporção dos comonômeros utilizadas para preparar os copolímeros. Enquanto que, todos os filmes de poli(TTF-co-DNBP) exibiram mudança de coloração entre o alaranjado no estado reduzido para marrom no estado oxidado. Essas mudanças são mais significativas nos filmes de poli(DQT-co-DNBP) na proporção 1:5 e nos filmes de poli(TTF-co-DNBP) na proporção 1:8 como mostrado nas coordenadas de cromaticidade xy CIE 1931 e pelos parâmetros eletrocrômicos. Os filmes de poli(DQT-co-DNBP) na proporção 1:5 (espessura 0,8 ± 0,2 µm) apresentaram contraste cromático (ΔT%) em 660 nm de 62%, eficiência coulômbica de 48%, eficiência eletrocrômica (η) de ~ 230 C cm-2 e estabilidade redox (atingindo ΔT% = 17% em λ = 660 nm no 1000º ciclo). Já os filmes de poli(TTF-co-DNBP) na proporção 1:8 (espessura 1,0 ± 0,2 µm) apresentaram eficiência coulômbica de aproximadamente 81 %, contraste cromático da ordem de 48 % em λ = 1065 nm e eficiência eletrocrômica na faixa de 180 C cm-2 para com boa estabilidade até 700 ciclos de carga/descarga. As soluções de poli(DQT) e poli(TTF) e de seus copolímeros com DNBP (independentemente da proporção) em N-metilpirrolidona (NMP) são fluorescentes. Os copolímeros de poli(DQT-co-DNBP) possuem emissões de bandas em 555 e 585 nm quando excitados em 375 nm e os copolímeros de poli(TTF-co-DNBP) emitem em 516 e 548 nm quando excitados em 450 nm. Portanto, esses copolímeros são promissores como materiais que possuem propriedades eletrocrômicas e fluorescentes, podendo ser aplicados como camada ativa em dispositivos optoeletrônicos, tais como dispostivos eletrocrômicos e OLEDs.

Made available in DSpace on 2014-10-09T12:52:00Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:06Z (GMT). No. of bitstreams: 0 / A finalidade deste trabalho de pesquisa foi a obtenção de matrizes poliméricas imobilizadas com a crotoxina, proveniente do veneno bruto de cascavel. Foram obtidas duas matrizes: (a) copolímero de enxerto para a imobilização da crotoxina, (b) micro-esferas de épisolon-policaprolactona (PCL) com crotoxina encapsulada. A crotoxina, proveniente da serpente Crotalus durissus terrificus (cascavel da América do Sul), após a sua purificação, foi caracterizada bioquímica e biologicamente. O resultado da avaliação da dose letal média (DL50) da toxina foi de 0,09mg/Kg de animal. O teste de citotoxicidade apresentou resultados semelhantes entre as células tumorais e os respectivos controles das células normais. Copolímeros de polietileno de baixa densidade enxertado com poli(metacrilato de 2-hidroxietila) (PEBD-g-PHEMA) foram utilizados como suportes para a imobilização química da crotoxina purificada. Para tal utilizou-se o polietileno de baixa densidade (PEBD) juntamente com o monômero hidrofílico metacrilato de 2-hidroxietila (HEMA). Os copolímeros foram obtidos via radiação ionizante, em fonte de cobalto 60 (60Co), e apresentaram graus de enxertia que variaram de 2 a 50%. Na caracterização por espectroscopia em infravermelho (ATR) observou-se os grupos funcionais principais do copolímero, em relação ao polímero base e PHEMA formado na irradiação. No perfil espectroscópico do copolímero estavam presentes bandas atribuídas aos grupos C=O (carbonila) e –OH (hidroxil), provenientes do homopolímero PHEMA. As micrografias do MEV do PEBD apresentaram superfícies lisas, enquanto que PEBD-g-PHEMA com alto grau de enxertia (32 %) revelou superfície rugosa devido à presença de PHEMA. O copolímero foi caracterizado fisicamente com o teste de hidrofilicidade, no qual o conteúdo de água foi determinado gravimetricamente. Com o coeficiente de difusão obtido pôde-se notar vii que a partir de 30 % de enxertia o copolímero torna-se menos hidrofílico, devido ao aumento das ligações cruzadas entre as cadeias de PHEMA. O teste de citotoxicidade revelou que PEBD-g-PHEMA pode ser utilizado como biomaterial. O copolímero imobilizado, crotoxina encapsulada e a crotoxina livre foram avaliados “in vivo” em camundongos da linhagem C3H. Durante 20 dias foram observados alterações de peso e comportamento, além das funções motoras. Os resultados demonstraram que o grupo injetado com crotoxina teve uma perda de peso maior do que os demais grupos. Concluindo, a crotoxina imobilizada nos copolímeros poderia ser utilizada pela sua ação catalítica foslipásica, na hidrólise dos fosfolipídeos presente nas lipoproteínas de baixa densidade (LDL) do soro humano. Por outro lado, a crotoxina encapsulada nas micro-esferas de poli(épsilon-caprolactona) (PCL) poderia ser utilizada como sistema de liberação dirigida (local) da crotoxina, destinada a terapia tumoral. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:25:29Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:52Z (GMT). No. of bitstreams: 1 06214.pdf: 4999286 bytes, checksum: 745d696fac5a880408cff8ed88614758 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Les travaux présentés dans cette thèse portent sur la polymérisation radicalaire de l'éthylène en émulsion, dans des conditions douces (P < 250 bar et T < 90 °C). Tout d'abord, l'homopolymérisation de l'éthylène a été étudiée. Des latex stables de polyéthylène présentant des taux de solide relativement élevés (30 %) ont été obtenus. Pour cela, deux systèmes différents d'amorçage et de stabilisation (cationique et anionique) ont été employés. Ces latex peuvent trouver des applications comme revêtements hydrophobes (par exemple du papier). L'étude des propriétés thermiques des latex a mis en évidence des phénomènes de cristallisation du polyéthylène à basse température, dû à son confinement dans les nanoparticules. Cela a une forte influence sur les morphologies finales des particules. D'autre part, la copolymérisation radicalaire de l'éthylène en émulsion a été étudiée. Les comonomères utilisés sont le styrène, l'acrylate de butyle, le méthacrylate de méthyle et l'acétate de vinyle qui différent par leur solubilité dans l'eau et leurs rapports de réactivité de copolymérisation avec l'éthylène. La composition des copolymères obtenus influence leurs propriétés thermiques (Tg, Tf). Des latex stables de copolymères de compositions variées ont pu ainsi être synthétisés. Ce travail en homo- et copolymérisation a souligné la complexité des milieux de polymérisation en émulsion impliquant un monomère gazeux supercritique comme l'éthylène / In this work, the free radical emulsion polymerization of ethylene under mild conditions (P < 250 bar and T < 90 °C) was investigated. Ethylene homopolymerization was first studied. Stable polyethylene latexes of significantly high solids content (30 %) were produced. This was achieved by the use of two different initiating and stabilizing systems (cationic and anionic). These latexes could be applied as hydrophobic coatings (e.g. on paper). Investigation of the thermal properties of the latexes evidenced crystallization phenomena at low temperatures, owing to PE confinement in the nanoparticles, which strongly impacted their final morphologies. Free radical emulsion copolymerization of ethylene was then studied. The investigated comonomers were styrene, butyl acrylate, methyl methacrylate and vinyl acetate. They differ in their reactivity ratios to ethylene and their water solubility. The composition of the obtained copolymers had a strong influence on their thermal properties (Tg, Tm). Stable latexes containing copolymers of various compositions were thus synthesized. This work on homo- and copolymerization evidenced the complexity of the polymerization media involving a gaseous supercritical monomer such as ethylene

The aim of the study will be the determination of the kinetic profiles of the polymerization of propene, ethene and their mixtures with commercial Ziegler-Natta catalyst by application of two different experimental procedures. The prepared polymer material will be utilized for the SEC analysis and subsequent evaluation of the concentration of active sites. The determined molecular mass distribution curves will be further investigated by the application of the procedure, which deconvolute the overall profile on the basic Flory's distribution functions. Then the comprehensive study about character and behavior of various types of active centers in dependence on time and type of monomer will result from this investigation.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22470号 / 工博第4731号 / 新制||工||1739(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 大内 誠, 教授 秋吉 一成, 教授 竹中 幹人 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The purpose of this work was the synthesis of functional amphiphilic gradient copolymers by means of controlled radical polymerizations, more precisely Atom Transfer Radical Polymerization. Two different monomer combinations, tert- and n-butyl methacrylate and tert-butyl and benzyl methacrylate, were copolymerized. In a first step seven different linear statistical copolymers were synthesized by means of batch polymerization. They were used as comparative material and the analysis of the reaction kinetic yielded the effective rate constants and the copolymerization parameters of the monomers in the particular monomer systems. Furthermore required for gradient polymer syntheses AB-di-block copolymers were synthesized as a second kind of comparative material. With the results of the kinetic analysis the monomer addition programs for the semibatch polymerizations were calculated to prepare gradient copolymers. Four different gradient copolymers with different compositions of tBMA and nBMA (ftBMA= 0.5, 0.65, 0.75, 0.85) and one gradient copolymer of tBMA and BzMA (ftBMA= 0.5) were synthesized. All semibatch reactions proceeded controlled, i. e. with mostly suppressed termination reactions. The compositions of the resulting copolymers exhibited ''double-gradients''. The point of change of the compositions were located at 16%, respectively 11% of conversion. The effective compositional gradients φ = dF1/dp were φ = 0.53, 0.46, 0.28, 0.15 and 0.43. A systematic correlation between the thermal behavior of the gradient copolymers and their composition was not found, as opposed to the statistical and the di-block copolymers. Semibatch synthesis with online infrared-spectroscopy observation to control the monomer feed during the synthesis were used for the polymerization of gradient copolymers. It was not possible to calculate the change of compositions of the polymers because it was not known how much monomer was injected at a certain time of the polymerization. A second problem was that the experimental set-up was not gas-tight. Hence, oxygen led to termination reactions. Three different kinds of hydrolysis were investigated for the cleavage of the tert-butyl groups on the polymer chains. The obtained gradient copolymers were hydrolyzed with methanesulfonic acid to obtain the intended amphiphilic polymer chains. All reactions proceeded with quantitative conversion. Hence, functional amphiphilic copolymers were obtained.

A fourth generation multiple site Ziegler-Natta catalyst was used to synthesize ethylene and propylene homo-and copolymers in the presence of hydrogen. This type of catalysts produce polymers with broader molecular weight distribution (MWD), chemical composition distribution (CCD) and stereoregularity than other coordination polymerization catalysts since it has more than one active site. The ratio of propylene/ethylene was varied to study its effect on polymer microstructure. In addition, by having two different electron donors, namely diisopropyldimethoxysilane (P) and dicyclopentyldimethoxysilane (D), the molecular weight distribution (MWD) and stereospecificity of the synthesized polymers were examined. The polymer samples were characterized using 13C-NMR and high-temperature gel permeation chromatography (GPC). Using the 13C-NMR data, the triad distribution for the copolymers and also the isotactic triad distribution for homo-polymers were calculated. The effects of electron donors on different feed ratios of ethylene and propylene in the synthesis were investigated. Co-polymer produced with D-donors showed higher isospecificity and also higher content of ethylene in the final polymer. In contrast, polymers produced using with P-donor showed lower polydispersity indices (PDI), and had higher contents of propylene in final polymer. In addition, the “Deconvolution method” was applied to GPC data in order to determine the number of sites on the Ziegler-Natta catalyst; which showed that 4 active site types were adequate to explain the molecular weight distributions.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24636号 / 工博第5142号 / 新制||工||1982(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 大内 誠, 教授 秋吉 一成, 教授 大北 英生 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM