Neste trabalho uretanas livres de isocianatos produzidas a partir de um precursor bis(ciclocarbonato) oligomérico contendo segmentos de poli(dimetil siloxano) (CCPDMS) foram sintetizadas. Para tal, utilizou-se diferentes aminas primárias como a 3-aminometil-3,5,5 trimetilciclohexilamina (IPDA) e as monoaminas 3-aminopropil(trietóxisilano) (APTES), feniletilamina (PEA), catecol amina (dopamina) e um decapeptídeo derivado da proteína de adesão de mariscos (mefp-1).O precursor oligomérico CCPDMS foi produzido por fixação de dióxido de carbono em anéis epóxi catalisado por um sal quarternário de amônio, o brometo de tetraetilamônio (BTA). O precursor CCPDMS foi então reagido com as aminas por meio de polimerização por abertura de anel formando hidroxiuretanas derivadas de PDMS (PDMSUr) com diferentes terminações de cadeia. Tendo como terminador de cadeia o APTES, foi possível produzir um material híbrido com domínios inorgânicos de sílica organicamente modificada (ormosil) interligadas com a parte orgânica de PDMS por meio de ligações uretana. Nesta matriz híbrida foram adicionadas diferentes porcentagens mássicas de ácido fosfotúngstico (PWA), variando entre 1% a 55%. Os materiais foram caracterizados quanto à sua estrutura química por técnicas espectroscópicas (Ressonância Magnética Nuclear, Infravermelho, Espectroscopia de Fotoelétrons, MALDI-ToF), propriedade anti-corrosão (espectroscopia de impedância eletroquímica, polarização potenciodinâmica), propriedades superficiais (energia livre superficial, nanoindentação), análise morfológica (Microscopia Eletrônica de Varredura), estabilidade térmica (Análise Termogravimétrica), testes de adesão (pull-off-test e cisalhamento), testes microbiológicos (adesão de bactérias, tecidos e citotoxicidade), além de ensaios de fotocromismo. O polioxometalato PWA conferiu propriedades fotocrômicas aos filmes híbridos de PDMSUr com máxima absorbância de 1,6 u.a após irradiação por luz ultra-violeta (UV). PDMSUr híbridas com ou sem PWA foram testadas como adesivos para vidro, alumínio, aço (SS316L) e liga de titânio (Ti6Al4V) apresentando valores de força de adesão entre 2-7 MPa. Filmes de PDMSUr preparados em diferentes substratos apresentaram comportamento bacteriostático frente à adesão de Escherichia coli (E.coli) e Lactobacillus casei (L.casei). A PDMSUr biomimética terminada por grupos catecóis foi capaz de formar camadas em superfícies metálicas apresentando boa estabilidade frente à remoção da camada depositada por lavagem com etanol. / Free isocyanate urethanes produced from an oligomeric precursor bis(cyclic carbonate) bearing poly(dimethylsiloxane) (CCPDMS) were synthesized in this work. Different primary amines such as 3-Aminomethyl-3,5,5-trimethylcyclohexylamine (IPDA) and monoamines 3-aminopropyltriethoxysilane (APTES), phenylethylamine (PEA), catechol amine (dopamine) and a decapeptide derived from marine mussel foot protein (mefp-1). The precursor cyclic carbonate CCPDMS was obtained from carbon dioxide fixation into epoxy rings catalized by a quaternary ammonium salt, tetraethylamonium bromide (TEAB). The precursor CCPDMS was reacted with the different amines by ring opening polymerization affording the formation of hydroxyurethanes PDMS derived (PDMSUr) with different chain terminations. Using APTES as chain terminator was feasible to obtain a hybrid material containing inorganic domains of organically modified silica (ormosil) interconnected to the organic part PDMS through urethane bond. In this hybrid matrix different mass percentages, varying from 1%wt to 55 wt%, of phosphotungstic acid (PWA) were added. The materials were characterized regarding their chemical structure by spectroscopic techniques (Nuclear Magnetic Resonance, Infrared, and X-ray photoelectron spectroscopy), mass spectrometry (MALDI-ToF and GPC), anti corrosive property (Electrochemical Impedance Spectroscopy and potentiodynamic polarization), surface properties (free surface energy, nanoindentation), morphology (Scanning Electron Microscopy), thermal stability (Thermogravimetric analysis), adhesion strenght measurements (pull-off-test and lap-shear), microbiologic assays (bacteria adhesion, tissue adhesion and citotoxicity test) besides photochromic assays. The polyoxometalate PWA provided photochromic property to the PDMSUr hybrid films presenting a maximum absorbance of 1.6 a.u after ultraviolet (UV) irradiation. Hybrids PDMSUr with or without PWA were tested as adhesive for glass, aluminium, steel (SS316L) and titanium alloy (Ti6Al4V) showing adhesion strength values ranging from 2-7 MPa. PDMSUr films prepared on different substrates showed bacteriostatic behavior against Escherichia coli (E.coli) and Lactobacillus casei (L.casei). The biomimetic PDMSUr catechol endcapped was able to form a layer on metallic surfaces showing good stability after rinsing with ethanol.

Part I . Mechanistic intermediates were discovered in the Henry condensations of partially and non-protected pyranoses with a free anomeric hemiacetal function with nitromethane in various solvents for the syntheses of C-glycopyranosides in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)/molecular sieves catalyst system. Part II . Syntheses of glycosyl cyanides were optimized with a new catalyst system. Mechanism of cyanation with trimethylsilyl cyanide (TMS-CN) in the presence of the mild and recyclable Lewis acid HgBr 2 in nitromethane were proposed for the syntheses of 1,2-trans per- O -acetylated C-glycopyranosyl cyanides. Part III . Tri-O-acetyl-β-L-fucopyranosyl cyanide and Pd-H 2 , in presence of BOC-anhydride, gave N-BOC-mono- and -di-(2,3,4-tri-O-acetyl-β-L-fucopyranosylmethyl)-amines, which allow for the syntheses of small cluster oligosaccharide mimetics of fucopyranosylomethyl-substituted ureas. From di-(2,3,4-tri-O-acetyl-β-L-fucopyranosylmethyl) amine was also prepared a carbamoyl chloride as potentially useful synthon for preparation of more complex C-glycosidic conjugates.

L'objectif de cette recherche est d'établir des mécanismes de formation de la structure des systèmes hybrides organique-inorganique à base des oligomères uréthane et silicates en fonction de la réactivité de la composant organique, d'identifier l'impact de l'organisation structurelle du OIS obtenue sur leurs propriétés électriques et thermomécaniques, de sorption et de l'activité du capteur. La signification pratique des résultats est la détermination de l'impact de la réactivité composant organique sur la structure des systèmes hybrides polymère organique-inorganique avec la possibilité d'obtenir des matériaux avec des propriétés spéciales prévisibles. Les résultats peuvent être utilisés comme base scientifique pour comprendre l'interconnexion de la structure, les propriétés et les moyens de leur régulation en direction de systèmes hybrides polymère organique-inorganique. La sensibilité très élevée pour les différents types de solvants, qui, combiné avec une haute sélectivité, a été révélé pour les systèmes de synthèse, la possibilité de leur utilisation pratique en tant que matières capteur existe.

L'objectif de cette recherche est d'établir des mécanismes de formation de la structure des systèmes hybrides organique-inorganique à base des oligomères uréthane et silicates en fonction de la réactivité de la composant organique, d'identifier l'impact de l'organisation structurelle du OIS obtenue sur leurs propriétés électriques et thermomécaniques, de sorption et de l'activité du capteur. La signification pratique des résultats est la détermination de l'impact de la réactivité composant organique sur la structure des systèmes hybrides polymère organique-inorganique avec la possibilité d'obtenir des matériaux avec des propriétés spéciales prévisibles. Les résultats peuvent être utilisés comme base scientifique pour comprendre l'interconnexion de la structure, les propriétés et les moyens de leur régulation en direction de systèmes hybrides polymère organique-inorganique. La sensibilité très élevée pour les différents types de solvants, qui, combiné avec une haute sélectivité, a été révélé pour les systèmes de synthèse, la possibilité de leur utilisation pratique en tant que matières capteur existe. / The aim of the research is to establish mechanisms of structure formation of hybrid organic-inorganic systems based on urethane oligomers and silicates, depending on reactivity of organic component, to identify the impact of structural organization of OIS obtained on their electrophysical and thermomechanical properties, sorption and sensor activity.The practical significance of the results is the determination of the impact of organic component reactivity on the structure of hybrid organic-inorganic polymer systems with the possibility of obtaining of the materials with predictable special properties. The results can be used as scientific basis for understanding the interconnection of structure, properties and ways of their directional regulation of hybrid organic-inorganic polymer systems. Whereas, the extremely high sensitivity to different types of solvents, which combined with the high selectivity, was revealed for the synthesized systems, the possibility of their practical use as sensor materials exists.