The overall goal of this research is to synthesize two different monomers for proton exchange membrane (PEM) Fuel Cells. Such monomers are proposed to be polymerized to improve the efficiency and compatibility of electrodes and electrolytes in PEM fuel cells. The first target is to synthesize 4-diazonium-3-fluoro PFSI zwitterionic monomer. Three steps were carried out in the lab. First one was the ammonolysis of 3-fluoro-4-nitrobenzenesulfonyl chloride. Second reaction was the bromination of Nafion monomer. The next coupling reaction, between brominated Nafion monomer and the 3-fluoro-4-nitrobenzenesulfonamide, was failed. The obstacles involve the harsh reaction condition and troublesome purification procedure. The second target is to synthesize 5-nitro-1, 3-benzenedisulfonamide. According to the literature, this synthesis was also designed as three steps: 1)nitration of sodium 1, 3-benzenedisulfonate salt; 2)chlorination of sodium 5-nitro-1, 3-benzenedisulfonate salt; and 3)ammonolysis of 5- nitro-1, 3- benzenedisulfonyl chloride. This monomer is expected to be copolymerized for membrane electrolyte in PEM fuel cells.

Die vorliegende Arbeit beschäftigt sich mit der Synthese monodisperser, multifunktionaler Poly(amidoamine) (PAAs). Die Klasse der PAAs ist besonders interessant für eine Anwendung im Bereich der Biomedizin, da sie meist nicht toxisch ist, eine sehr geringe Immunogenizität zeigt und eine erhöhte Zellmembranpermeabilität besitzt. Allerdings ist der Einsatz linearer PAAs bisher limitiert, da ihre Synthese nur den Zugang von hoch-polydispersen Systemen mit einer streng alternierenden oder statistischen Verteilung von Funktionalitäten erlaubt. Es ist daher von großem Interesse diese Polymerklasse durch die Möglichkeit eines sequenzdefinierten Aufbaus und der Integration von neuen Funktionalitäten zu verbessern. Um dies zu ermöglichen, wurden, vergleichbar mit der etablierten Festphasensynthese von Peptiden, schrittweise funktionale Disäure- und Diamin-Bausteine an ein polymeres Träger-Harz addiert. Der sequenzielle Aufbau ermöglicht die Synthese monodisperser PAAs und die Kontrolle über die Monomersequenz. Die Wahl der Monomer-Bausteine und ihrer Funktionalitäten kann dabei für jede Addition neu getroffen werden und entscheidet so über die Sequenz der Funktionalitäten im Polymerrückgrat. Die verwendete Chemie entspricht dabei der Standardpeptidchemie, so dass mit Hilfe eines Peptidsynthese-Automaten die Synthese vollständig automatisiert werden konnte. Die Verwendung spezieller Trägerharze, die bereits mit einem synthetischen Polymerblock wie PEO oder auch mit einem Peptid vorbeladen waren, erlaubt die direkte Synthese von PEO- und Peptid-PAA Blockcopolymeren. Da die hier dargestellten PAAs später auf ihre Eignung als multivalente Polykationen in der Gentherapie getestet werden sollten, wurden zunächst Bausteine gewählt, die den Einbau verschiedener Aminfunktionalitäten ermöglichen. Die Bausteine müssen dabei so gewählt sein, dass sie kompatibel sind mit der Chemie des Peptidsynthesizers und eine quantitative Addition ohne Neben- oder Abbruchreaktionen garantieren. Darüber hinaus ist der Einbau von Peptidsequenzen und Disulfid-Einheiten in die PAA-Kette möglich, die z. B. für einen selektiven Abbau des Polymers im Organismus genutzt werden können. Zusammenfassend lässt sich feststellen, dass die in dieser Arbeit vorgestellten PAA-Systeme großes Potenzial als nicht-virale Vektoren für die Gentransfektion bieten. Sie sind nicht toxisch und zeigen Zellaufnahme-Effizienzen von bis zu 77%. Die Gentransfereffizienz ist im Vergleich zu etablierten Polymer-Vektoren zwar noch sehr gering, aber die bisherigen Versuche zeigen bereits eine mögliche Ursache, nämlich die schlechte Freisetzung des Genmaterials innerhalb der Zelle. Eine Lösung dieses Problems bietet jedoch die weitere Modifizierung der PAA-Systeme durch den Einbau von Sollbruchstellen. Diese Sollbruchstellen ermöglichen einen programmierten Abbau des Polymers innerhalb der Zelle und damit sollte die Freisetzung des Genmaterials vom Träger deutlich erleichtert werden. Mögliche Bruchstellen sind z. B. enzymatisch gezielt spaltbare Peptideinheiten oder Disulfid-Einheiten, wie sie bereits als Bausteine für die PAA-Synthese vorgestellt wurden (vergl. Kapitel 4.4). Da nur innerhalb der Zelle ein reduzierendes elektrochemisches Potential besteht, werden z. B. Disulfid-Einheiten auch nur dort gespalten und bieten außerhalb der Zelle ausreichende Stabilität zum Erhalt der Polyplexstruktur. Neben einer Anwendung in der Gentherapie bieten die hier vorgestellten PAA-Systeme den Vorteil einer systematischen Untersuchung von Struktur-Eigenschafts-Beziehungen der Polyplexe. Es wurden verschiedene Zusammenhänge zwischen der chemischen Struktur der PAA-Segmente und der Art und Stärke der DNS-Komprimierung aufgezeigt. Die Komprimierungsstärke wiederum zeigte deutlichen Einfluss auf die Internalisierungsrate und damit auch Transfektionseffizienz. Darüber hinaus zeigte sich ein drastischer Einfluss des PEO-Blocks auf die Stabilisierung der Polyplexe sowie deren intrazelluläre Freisetzung bei Zusatz von Chloroquin. Dennoch bleiben aufgrund der Komplexität der Zusammenhänge noch viele Mechanismen der Transfektion unverstanden, und es muss Aufgabe folgender Arbeiten sein, das Potential der hier eingeführten monodispersen PAA-Systeme weiter auszuloten. So wäre z. B. eine Korrelation der Kettenlänge mit den Parametern der Polyplexbildung, der Zellaufnahme und Transfektionseffizienz von großem Interesse. Darüber hinaus bietet der Einbau von Sollbruchstellen wie kurzen Peptidsequenzen oder den hier bereits eingeführten Disulfid-Einheiten neue Möglichkeiten der gezielten Freisetzung und des programmierten Abbaus, die näher untersucht werden müssen. Neben der Anwendung im Bereich der Gentransfektion sind außerdem andere Gebiete für den Einsatz von monodispersen multifunktionalen PAAs denkbar, da diese kontrollierbare und einstellbare Wechselwirkungen ermöglichen. / Recently, linear poly(amidoamine)s (PAAs) have received considerable attention due to their excellent biocompatibility and ease of synthesis.[1] PAAs are multifunctional polymers, which often exhibit low inherent immunogenicity and reduced cyto- as well as hemotoxicity in contrast to established, cationic polymers such as poly(ethylene imines) (PEI) or poly(L-lysines) (PLL).[2] This makes PAAs highly suitable for biomedical and pharmacological applications in the fields of drug and gene delivery.[1,2] However, the full potential of these polymers cannot be accessed since the synthesis proceeds via an uncontrolled polyaddition reaction leading to ill-defined products with Mw/Mn ≥ 2. This does not only make rational design of polymer properties and the precise positioning of functionalities along the polymer backbone difficult, furthermore product registration becomes complicated because legislation requires increasingly more defined products. Here we present a novel synthesis route towards multifunctional, sequence-defined polyamides.[3] A fully automated, solid-phase polymer synthesis was developed and utilized to obtain linear PAA segments. These exhibit no molecular weight or chemical distributions due to their monodispersity (Mw/Mn = 1) and their controlled monomer sequence. The compatibility of the PAA-synthesis with the standard Fmoc/tBu solid-phase supported peptide synthesis has been preserved, making this route a versatile approach to peptide-PAA (Pep-PAA) and poly(ethylene oxide)-PAA (PEO-PAA) conjugates. Several Pep-PAA and PEO-PAA conjugates were synthesized, exhibiting PAA segments with different cationic functionalities. These conjugates were analyzed concerning their cytotoxicity showing very promising results. Additionally their potential to complex plasmid-DNA and to form so-called polyplexes for non-viral gene delivery was tested. A strong relationship between the monomer sequence and the polyplex structure was observed, depending on the balance and total amount of tertiary, secondary and primary amine functionalities within the PAA-segment. Moreover the monomer sequence has a strong influence on the biological properties such as the cell-internalization of polyplexes as well as the transfection activity. This clear correlation between the chemical assembly and the resulting biological properties may help to further the understanding of the mechanisms of gene delivery by polymeric carriers and hence to promote the rational design of better suited systems. Even if the transfection activity for the PAA-polpylexes might still be not comparable to the established “gold standard” PEI, their low level of toxicity and the possibility to improve the system by adjusting the monomer sequence shows great potential as carrier systems in drug or gene delivery.

The development of materials for advanced applications requires innovative macromolecules with well-defined structures and the inherent ability to be tailored in a straightforward manner. Dendrimers, being a subgroup of the dendritic polymer family, possess properties which fulfill such demands. They have a highly branched architecture with a high number of functional groups and are one of the most well-defined types of macromolecules ever synthesized. However, despite their well-defined nature and high functional density, traditional dendrimers commonly lack diverse chemical functionalities. Therefore, this thesis focuses on the synthesis of more complex dendritic materials to extend their tailoring capacity by introduction of dualfunctionalities for multipurpose actions. It covers the synthesis of dualfunctional dendrimers, dendritic modification of linear poly(ethylene glycol) polymers and cellulose surfaces, and the synthesis of linear dendritic hybrids. The building blocks enabling this synthesis, AB2C monomers, were also developed during this work. The orthogonal nature between click groups (azide, alkyne and alkene) and hydroxyl groups have efficiently been utilized for postfunctionalization by robust click chemistry and traditional esterification reactions. Furthermore, linear dendritic hybrids were synthesized, merging the properties of linear and dendritic macromolecules. The dendritic frameworks were tailored towards the production of bone fracture adhesives, novel biofunctional dendritic hydrogels, biosensors and micellar drug delivery vehicles. / Utveckling av material för avancerade applikationer kräver innovativa makromolekyler med väldefinierade strukturer och som kan skräddarsys på ett enkelt sätt. Dendrimerer är en undergrupp av dendritiska polymerer vars egenskaper uppfyller dessa krav. De har en mycket förgrenad arkitektur med många funktionella grupper och är en av de mest väldefinierade befintliga syntetiska makromolekylerna. Trots dess väldefinierade karaktär och höga funktionalitet saknar ofta traditionella dendrimerer multipla kemiska funktionaliteter. Denna avhandling fokuserar därför på syntesen av mer komplexa dendritiska material för att förbättra deras kapacitet att skräddarsys, detta görs genom att introducera fler funktionaliteter som kan utnyttjas för multipla ändamål . Avhandlingen redogör för syntesen av difunktionella dendrimerer, dendritiska modifikationer av polyetylenglykol och cellulosaytor samt syntes av traditionella dendritiska hybrider. Byggstenarna som möjliggör syntesen, AB2C monomerer, framställdes också under detta arbete. Den ortogonala karaktären mellan klick grupper (azid, alkyn och alkene) och hydroxylgrupper har utnyttjats effektivt för funktionaliseringar genom användande av robust ”Click”-kemi och traditionella esterifikationsreaktioner. Vidare tillverkades de linjära dendritiska hybrider för att kombinera egenskaperna hos både linjära och traditionella dendritiska polymerer i en och samma makromolekyl. Samtliga dendritiska strukturer skräddarsyddes för applikationer så som benlimmer, biofunktionella dendritiska hydrogeler, biosensorer och läkemedels-bärande miceller. / <p>QC 20130830</p>

The synthesis of enantiopure compounds can be achieved by using dehydrogenases as biocatalysts. For instance, reduction reactions of prochiral compounds (ketones, aldehydes and nitriles) into chiral compounds can be achieved by dehydrogenases. These dehydrogenases are cofactor dependent where cofactor is Nicotinamide Adenin Dinucleotite having some restrictions that confines usage of dehydrogenases in organic synthesis including instability of cofactor in water and high cost. Therefore, suitable recycling methods are required and developed which are enzymatic and electrochemical. We will use an electrochemical approach for the regeneration of reduced co-factors. All active compounds / mediator, cofactor and enzyme, will be immobilized on the electrode surface of the constructed reactor surface. Therefore only educts and products will exist in the reactor medium. A gas diffusion electrode will be employed as a counter electrode / which delivers clear protons to the system. Mediator will carry electrons to the cofactor for cofactor regeneration. Then, enzyme will utilize the cofactor and change the substrates to the products in high stereoselectivity. Our aim in this project is the synthesis of mediators and suitable linkers for enzyme, cofactor and mediator immobilization. In the first part of the study, mediators were synthesized which are pentamethylcyclopentadienyl rhodium bipyridine complexes. In the second part of the study, a conductive monomer (SNS) and linker were synthesized for immobilization of the enzyme. In the last part of the study, the reaction of galactitol dehydrogenase with monomer (SNS) was achieved.

La thèse est orientée à la production d'une membrane proton conductrice pour la pile à combustible à membrane proton électrolyte (PEMFC) comme un but principal. L'originalité et le challenge de l'élaboration de la membrane consistent en procédure multi-étape : commencer avec la synthèse de l'unité simple – un monomère ionique, continuer avec la polymérisation et l'estimation générale de performance en échelle de laboratoire de polymère ; et finir avec la production des matériaux en échelle industrielle et tester en conditions réelles. Toutes les étapes, sauf la dernière, sont étudiées en détail. Premièrement, beaucoup d'attention est portée à la description du protocole de production et purification de monomères ioniques. C'est à cause de la complexité des interactions ioniques dans un système ‘produit-solvant' et dû à l'exigence principale pour la haute pureté du monomère que la synthèse et traitement attentifs des monomères doivent être faits. En total, trois nouveaux monomères, portants les chaines acides perfluorosulfoniques, sont proposés. Ensuite, plusieurs réactions de polymérisation avec les différents monomères non-ioniques commerciaux sont décrites. Deux familles différentes des membranes proton conductrices sont décrites : poly(arylene ether)s (PAEs) statistiques et poly(arylene ether sulfone)s statistiques et en bloc. Elles sont synthétisées en séries de CEI différentes pour pouvoir suivre l'impact du groupe ionique sur les propriétés des matériaux. De plus, la nouvelle structure d'ionomère est proposée, où le copolymère à bloc contient le bloc hydrophile, synthétisé de deux monomères, portants les groupes perfluorosulfoniques (PFSA). Ça permet d'approcher au maximum les groupes latéraux superacides le long de la chaîne, ce qui, le plus probablement, contribue vers la meilleur organisation t interaction entre les sites ioniques. Pour la caractérisation suivante des nouveaux polymères ils sont coulés en membranes par la méthode de coulée-évaporation de ses solutions en dimethylacétamide (DMAc). Influence de la température du processus est décrite brièvement. Les membranes de différentes séries sont comparées entre eux-mêmes et à Nafion comme le matériau de référence. C'est connu que Nafion acquiert sa haute performance dû à : i) présence du groupe latéral superacide PFSA et ii) organisation des chaînes de polymère aux domaines bien séparés de conducteurs de protons (hydrophiles) et stables mécaniquement (hydrophobes). Par contre, la production de ce matériau contient les procédures dangereuses et chères de manipulation avec les gases fluorés, car cet ionomère contient une chaîne de base de Teflon. De plus, la température de transition de squelette perfluorée est plus basse que la température de fonctionnement de ionomère dans PEMFC. Les nouveaux ionomères sont ensuite caractérisés pour les propriétés thermo-mécaniques, stabilité, conductivité, morphologie. Ils montrent : i) hautes températures de transitions, ce qui permet l'utilisation de ces polymères aux conditions de la fonctionnement de PEMFC ; ii) le phénomène de la séparation de phases, ce qui propose les matériaux d'avoir la morphologie avec les domaines bien définis pour la conduction des protons, iii) la structuration avec une organisation importante, ce qui est rare d'apercevoir pour les matériaux aromatiques ; iv) haute conductivité protonique même à l'humidité réduite pour plusieurs séries des polymères proposées. Par conséquent, les matériaux montrent la performance prometteuse, ce qui doit être vérifiée aux conditions réelles de la pile à combustible. De plus, ce travail est innovant par la procédure de production des ionomères, c'est pourquoi plus des différentes séries des polymères sont prévues à être synthètisées à partir des monomères ioniques proposés ici. La variation des monomères ioniques peut être élargie aussi par changement de PFSA groupes aux perfluorosulfonimides. / The current work is directed to production of a proton conducting membrane for a proton electrolyte membrane fuel cell (PEMFC) as a main goal. The originality and the challenge of the membrane elaboration lie in the multi-step procedure: starting with the synthesis of a simple unit – an ionic monomer, continuing with polymerization and overall estimation of the polymer performance at laboratory scale, and ending with production of the required material of industrial quantity and testing in real conditions. All the steps, except the last one, are explicitly studied. Firstly, much attention in the dissertation is paid to description of a protocol for production and purification of the ionic monomers. It is due to complexity of ionic interactions in a system ‘product-solvent' and due to the main requirement of high purity for a monomer that attentive synthesis and treatment of the monomers must be provided. In total three new monomers, bearing perfluorosulfonic acid chains, are reported. Then, a number of polymerization reactions with different commercial non-ionic monomers are proposed. Two main families of proton conducting ionomers are described: random poly(arylene ether)s (PAEs) and poly(arylene ether sulfone)s (PAESs), both random and block-copolymers. They are synthesized in series of different IEC in order to follow the impact of the ionic group to the properties of the material. Additionally, a new structure of the ionomer is proposed, where the block-copolymer contains a hydrophilic block, synthesized from two monomers, bearing perfluorosulfonic acid (PFSA) groups. It allows maximally approximating the superacid lateral groups along the polymer chain that, most probably, contributes to better organization and interaction between the ionic sites. For further characterization of the novel polymers, they are cast to membranes by casting-evaporation method from their solutions in dimethylacetamide (DMAc). The influence of production temperature is described briefly. The membranes of different series are compared between each other and to Nafion as a reference material. It is known that Nafion acquires its high performance due to: i) presence of superacid PFSA lateral groups, and ii) organization of polymer chains into well-separated proton-conductive (hydrophilic) and mechanically stable (hydrophobic) domains. However, production of this material comprises dangerous and expensive procedures of manipulation with fluorinated gases, since this ionomer contains a Teflon-type backbone. Moreover, transition temperature of the perfluorinated main chain is lower, than the required temperature of the ionomer functioning in a PEMFC. The novel ionomers are further characterized in terms of thermo-mechanical properties, stability, conductivity, bulk morphology. They exhibit: i) high transition temperatures, which allows utilization of these polymers at conditions of a PEMFC functioning; ii) phase separation phenomenon, which suggests the materials to have morphology with distinct domains for proton conduction, iii) highly organized structuring, which is rare to clearly evidence on aromatic materials; iv) high proton conductivity for several polymer series, which over-perform Nafion even at reduced humidity. Based on these results, some of the synthesized materials are considered to be promising in a PEMFC, but further study in real conditions must be provided. Additionally, the current work is pioneering in the way of production of the ionomers, therefore, more different series of polymers are previewed to be synthesized out of the ionic monomers, proposed here. Variety of the ionic monomers may be enlarged as well by changing the PFSA groups to perfluorosulfonimide ones or by searching for other fluorinated commercial materials that might be modified into monomers with two functional groups for polycondensation. Thus, the main objectives, set for the current work, are fulfilled.

A necessidade do aprimoramento das técnicas de confecção de próteses oculares que permitam satisfazer, com rapidez e excelência, a demanda de atendimento de pacientes portadores de perdas do bulbo ocular, levou ao desenvolvimento deste estudo comparativo no qual se avalia a porosidade superficial, absorção de água e liberação de monômero residual de resinas acrílicas. Foram estabelecidos quatro grupos de estudo, sendo cada grupo composto por 15 corpos de prova: Grupo 1 - resina acrílica termo polimerizável convencional / ciclo térmico convencional; Grupo 2 - resina acrílica termo polimerizável em microondas / ciclo microondas; Grupo 3 - resina acrílica termo polimerizável convencional / ciclo microondas; Grupo 4 - resina acrílica auto polimerizável com cadeia cruzada / auto polimerização. A avaliação da quantidade de monômero residual liberado foi realizada por meio de espectrofotometria, durante o período de 11 dias. A determinação da absorção de água baseou-se na diferença do peso apresentado pelos corpos de prova nas condições experimentais seco e após submersão em água deionizada por um período de 7 dias. A determinação da porosidade superficial foi calculada sob a forma de porcentagem por área de superfície analisada, empregando-se lupa estereoscópica para captação da imagem a ser processada pelo software ImageLab 2000®. Submetendo-se os dados à análise estatística ANOVA/TUKEY (p<=0,05) observou-se que a liberação de monômero residual foi significantemente maior no primeiro dia para o Grupo 1, semelhante durante todo o período para o Grupo 2, menor a partir do dia 8 para o Grupo 3 e decrescente até o dia 8 para o Grupo 4. A liberação de monômero residual foi semelhante para os Grupos 1 e 3, menor para o Grupo 2 e maior para o Grupo 4. A absorção de água foi semelhante para os quatro grupos de estudo. A maior porosidade ocorreu no Grupo 2, sendo os Grupos 1 e 3 semelhantes entre si. Concluiu-se que os ciclos térmicos de polimerização em água e em microondas não interferiram na liberação de monômero residual da resina acrílica termo polimerizável convencional. A liberação de monômero residual variou em função do tipo de resina acrílica. O tipo de resina acrílica e o ciclo de polimerização a que foram submetidas não interferiram na absorção de água. Os ciclos térmicos de polimerização em água e em microondas não interferiram na porosidade apresentada pela resina acrílica termo polimerizável convencional. A porosidade superficial variou em função do tipo de resina acrílica avaliada. / This comparative evaluation of porosity, water sorption and residual monomer presented by acrylic resins was conducted, looking for excellence and rapidity in the confection of eye prostheses. Four groups, comprising of 15 specimens each, were established and submitted to polymerization cycles: Group 1 - conventional heat polymerizing acrylic resin / conventional heat-polymerization cycle; Group 2 - microwave acrylic resin / microwave cycle; Group 3 - conventional heat polymerizing acrylic resin / microwave cycle; Group 4 - cross-linked auto-polymerizing acrylic resin / auto-polymerizing process. Residual monomer liberation was determined by spectrophotometry during 11 days period. Water sorption was calculated by weighting dried specimens and weighting after 7 days of submersion in deionized water. Superficial porosity was determined by percentage of area, in images processed by the software ImageLab 2000®. Subjecting data to ANOVA/TUKEY test (p<=0,05) it was observed that residual monomer liberation was higher in the first day for Group 1, similar during all the period for Group 2, lower after day 8 for Group 3 and decreasing until day 8 for Group 4. Residual monomer liberation was similar to Groups 1 and 3, lower for Group 2 and higher for Group 4. Water sorption was similar to all groups. Group 2 displayed more superficial porosity, and Group 1 and 3 were similar regarding this test. In conclusion, conventional polymerization and microwave processes did not interfere in residual monomer liberation of conventional acrylic resin. The residual monomer liberation varied according the type of acrylic resin. Microwave cycle provided similar or smaller residual monomer liberation. The type of acrylic resin and the polymerization cycle utilized did not modify water sorption. The conventional heat polymerizing cycle and microwave cycle did not interfere in superficial porosity of conventional heat polymerizing acrylic resin. The superficial porosity varied according to the acrylic resin.

Made available in DSpace on 2014-08-20T14:30:13Z (GMT). No. of bitstreams: 1 Dissertacao_Marilia_Oliveira_Barbosa.pdf: 1068284 bytes, checksum: 523346df7ee3bd1a1ce4c3ee23aff3e8 (MD5) Previous issue date: 2011-03-31 / HEMA is a monomer widely used in the adhesive systems, although the biologic performance has been found as negative it has been tried to solve this problem by testing new monomers with lower citotoxic potential. We analyzed the biocompatibility of five experimental dimethacrylate monomers: Bis-EMA 10, Bis- EMA 30, PEG 400, PEG 400 UDMA, PEG 1000. First, it was made an in vitro test using 3T3 mouse fibroblast cell culture. So, the cytotoxic test was made using primers at 20% and 2%. The dilutions were maintained in contact with the cells for a period of 24h and after the survival these cells was verified photometrically using MTT assay. After it was performed cytotoxic test with the resin bonds as follows: hese monomers were polymerized and leaving in immersion in DMEM for 24h and later the eluate obtained was inserted on the 3T3 cell for 24h. The statistical analysis was performed by Kruskal wallis method, followed by a multiple-comparison Dunn´s test (p<0.05). Second, the degree of conversion of adhesive resin was also analyzed.The results showed that related to the primers in the concentration of 2% only PEG 1000 group had no statistical difference with the control group. In the concentration of 20% there was no difference among Bis-EMA 10, PEG 1000 and the control group. Concerning to eluates there were no difference among Bis-EMA 10, PEG 400 UDMA and the control group. All monomers showed a degree of conversion similar than HEMA. Other studies are necessary using different concentrations and different cell lines because these monomers are promising in the use of adhesive systems. / HEMA é o monômero mais utilizado nos sistemas adesivos, embora o desempenho biológico venha sendo negativo está se tentando resolver este problema testando novos monômeros com menor potencial citotóxico. Analizamos a biocompatibilidade de cinco monômeros dimetacrilatos: Bis-EMA 10, Bis-EMA 30, PEG 400, PEG 400 UDMA, PEG 1000. Para analisá-los foi feito teste in vitro com cultura de células 3T3 de fibroblastos de ratos. Primeiramente, um teste citotóxico foi feito usando primers em concentrações de 2% e 20%. As diluições ficaram em contato com as células por um período de 24 horas, e a quantidade de células viáveis foi avaliada por meio de espectrofotômetro infravermelho, usando ensaio MTT. Um segundo teste foi realizado nos adesivos. Eles foram polimerizados e deixados em imersão em DMEM por 24 horas e depois o eludato obtido foi inserido nas células 3T3 por 24 horas. Os dados foram submetidos ao teste não paramétrico Kruskal Wallis seguido pelo teste complementar de Dunn´s (p<0,05).O grau de conversão dos adesivos também foi analisado. Os resultados mostram que, em relação aos primers, na concentração de 2%, PEG 1000 não apresentou diferença estatística do controle. Na concentração de 20% não houve diferença com o Bis-EMA 10 e PEG 1000. Em relação ao eludato não houve diferença estatística com o Bis-EMA 10 e PEG 400 UDMA. Todos monômeros tiveram grau de conversão similar ao HEMA. Outros estudos são necessários usando diferentes concentrações e diferentes linhagens celulares porque esses monômeros são promissores no uso em sistemas adesivos.

L'association d'halogénure de tétraoctylammonium et de triisobutylaluminium permet de réaliser la polymérisation anionique de divers époxydes par activation du monomère. Ces systèmes catalytiques ont été appliqués à la (co)polymérisation de l'épichlorhydrine. Cette méthode qui a permis d'obtenir des poly(épichlorhydrine)s de masses molaires contrôlées jusqu'à 100 000 g/mol, a été étendue ensuite à la synthèse de copolymères, statistiques et à blocs, associant l'épichlorhydrine à divers oxiranes substitués : oxyde de propylène, éther tert-butyl glycidique et éther allyl glycidique. Dans le but d'élargir le domaine d'application de ces polyéthers ω-hydroxylés, l'introduction de groupements fonctionnels en tête de chaine a été étudiée. L'influence des substituants du dérivé aluminique et la nature de l'amorceur sur l'efficacité et la spécificité de l'amorçage ont été examinés. / Association of tetraoctylammonium halide and triisobutylaluminium allows anionic polymerization of epoxides by an activated monomer mechanism. This catalytic system was applied to the synthesis of (co)polymers of epichlorohydrin. The synthesis of poly(epichlorohydrin) was achieved in a controlled manner allowing the preparation of polymers with molar masses up to 100 000 g/mol. This approach was extended to the synthesis of statistic and block copolymers of epichlorohydrin with various substituted oxirane : propylene oxide, tert-butyl glycidyl ether and allyl glycidyl ether.In order to extend the application field of this ω-hydroxyl polyether, we have investigated the introduction of functional groups at the beginning of the polymer chain. For this purpose, the influence of the substituted group on the aluminium and the nature of the initiator were examined on the efficiency and the specificity of the initiation step.

A series of 3-(p-X-phenyl) thiophene monomers (X= –H, –CH3, – OCH3, –COOC2H5, –COCH3,–NO2) was electrochemically polymerized to furnish polymer films that could be reversibly reduced and oxidized (n- and p-doped). The oxidation potentials of the monomers and formal potentials of the n- and p-doping processes of polymers were correlated with resonance and inductive effects of the substituents on the phenyl ring as well as the semiempirically calculated heats of formation of the monomer radical cations. Moreover, the oxidation potentials of the monomers were correlated with the ionization potentials of the monomers calculated using density functional theory. The reactivity for coupling reactions and the major regioselective products of the polymerization reaction of mono- and oligo-3-phenylthiophenes are inferred from the calculated lone electron spin densities of the respective radical cations. The ionization potentials, which correspond to the energies for generating radical cations during oxidative processes were estimated.

No description available.