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Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Neste trabalho foram investigados os comportamentos térmico e mecânico e as características morfológicas de amostras de policarbonato de bisfenol-A (PC) com cristalinidade induzida por exposição ao vapor de solvente. A técnica de indução de cristalização foi empregada em três amostras de policarbonato de bisfenol-A de diferentes massas molares. Filmes vazados a partir de soluções de PC em clorofórmio e amostras moldadas por compressão foram expostos a um ambiente contendo vapor de acetona. Os filmes foram expostos por diferentes períodos de tempo e analisados em equipamentos de Calorimetria Diferencial de Varredura, Microscopia Óptica com luz polarizada e Espectroscopia na Região do Infravermelho com Transformada de Fourier, para caracterizar a indução de cristalinidade. A indução de cristalinidade foi confirmada e a fase cristalina apresentou estrutura esferulítica. As amostras de maior massa molar mostraram maior teor de cristalinidade. O desempenho mecânico das amostras cristalinas de policarbonato mostrou diferenças, com a mudança de seu comportamento mecânico de dúctil para frágil, independente da massa molar / In this work were investigated the thermal and mechanical behaviors and the morphological characteristics of bisphenol-A polycarbonate (PC) samples with crystalline induction by solvent vapor exposure. The crystallization induction technique was employed on three samples of bisphenol-A polycarbonate of different molar mass. Films cast from PC solutions in chloroform and compression molded samples were exposed to an environment containing acetone vapor. The films were exposed for different periods of time and analyzed on Differential Scanning Calorimeter, Polarized Light Optical Microscope and Fourier Transform Infra Red devices to characterize crystalline induction. The crystalline induction was confirmed and the crystalline phase has presented spherulitic structure. The highest molar mass samples have shown higher crystallinity degrees. Mechanical performance of crystalline samples has shown differences with the change of its mechanical behavior from ductile to fragile, independently of the molar mass

In this dissertation, we will study solvent-vapor induced spherulitic growth in multicomponent thin films modeled as prestressed elastic solids. The interface between the crystalline phase and the amorphous phase will be treated as an evolving thermodynamic system and no diffusion of any component will be considered. The dissertation is divided into three parts. In Part I we will determine necessary conditions of thermodynamic equilibrium between the two solid phases, the inter- face, and the vapor. In Part II we will derive the thermodynamic driving force for spherulitic growth in multicomponent elastic thin films. In Part III we will investigate the effect of prestress on the directional dependence of the growth. There a formula that delineates how the prestress affects the shape of the spherulite will be proposed.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Neste trabalho foram investigados os comportamentos térmico e mecânico e as características morfológicas de amostras de policarbonato de bisfenol-A (PC) com cristalinidade induzida por exposição ao vapor de solvente. A técnica de indução de cristalização foi empregada em três amostras de policarbonato de bisfenol-A de diferentes massas molares. Filmes vazados a partir de soluções de PC em clorofórmio e amostras moldadas por compressão foram expostos a um ambiente contendo vapor de acetona. Os filmes foram expostos por diferentes períodos de tempo e analisados em equipamentos de Calorimetria Diferencial de Varredura, Microscopia Óptica com luz polarizada e Espectroscopia na Região do Infravermelho com Transformada de Fourier, para caracterizar a indução de cristalinidade. A indução de cristalinidade foi confirmada e a fase cristalina apresentou estrutura esferulítica. As amostras de maior massa molar mostraram maior teor de cristalinidade. O desempenho mecânico das amostras cristalinas de policarbonato mostrou diferenças, com a mudança de seu comportamento mecânico de dúctil para frágil, independente da massa molar / In this work were investigated the thermal and mechanical behaviors and the morphological characteristics of bisphenol-A polycarbonate (PC) samples with crystalline induction by solvent vapor exposure. The crystallization induction technique was employed on three samples of bisphenol-A polycarbonate of different molar mass. Films cast from PC solutions in chloroform and compression molded samples were exposed to an environment containing acetone vapor. The films were exposed for different periods of time and analyzed on Differential Scanning Calorimeter, Polarized Light Optical Microscope and Fourier Transform Infra Red devices to characterize crystalline induction. The crystalline induction was confirmed and the crystalline phase has presented spherulitic structure. The highest molar mass samples have shown higher crystallinity degrees. Mechanical performance of crystalline samples has shown differences with the change of its mechanical behavior from ductile to fragile, independently of the molar mass

Dans un contexte de miniaturisation à l’extrème des composants électroniques, les copolymères àblocs apportent une réponse technologique alternative aux procédés conventionnels destructuration des matériaux par lithographie. Parmi les défis à relever, l’obtention de systèmes decopolymères suffisamment résolus demeure un élément essentiel pour que cette technique puisseoffrir une réelle alternative pour la lithographie sub-20 nm. Nous montrons au travers del’exemple du maltoheptaose-b-polystyène (MH-b-PS) que les copolymères biosourcés ont lacapacité d’atteindre une résolution sub-10 nm grâce à l’association d’un bloc hydrophile(l’oligosaccharide) et d’un bloc hydrophobe (le polystyrène). Les études par AFM, SAXS etGISAXS réalisées sur les films de MH-b-PS ont permis de montrer que le recuit sous vapeur desolvant est plus efficace que le recuit thermique pour organiser ce type de copolymère, composéd’un bloc sensible à la dégradation thermique. Ensuite, une étude inédite du recuit sous vapeur desolvant par QCM-D (Micro-balance à quartz avec mesure de dissipation) a été présentée et adémontré la capacité de cette technique à caractériser la quantité de solvant absorbée par le filmau cours du traitement ainsi que l’évolution de la viscoélasticité du film permettant ainsi d’obtenirdes informations indispensables à la compréhension du mode d’action du recuit sous vapeur desolvant. Finalement, l’étude en solution de ce copolymère ainsi que l’impact de la longueur deschaines des deux blocs sur la morphologie des films auto-organisés permettra de mieuxcomprendre à l’échelle de la chaine de polymère le comportement spécifique du MH-b-PS. / The constant desire of size reduction in nanoelectronic leads to develop processes, able to patternmaterials at the sub-10 nm scale. In this context, self-assembling block copolymers are promisingmaterials offering an alternative method to conventional lithography techniques. Currently, one ofthe major challenges in this field is to find copolymers that could address sub-10 nm pattern sizein order to provide a competitive process. In this thesis, we studied the maltoheptaose-bpolystyrene(MH-b-PS) and we showed that these kinds of sugar-based copolymers are able toself-assemble on a sub-10 nm scale thanks to the combination of a hydrophilic block (sugar) and ahydrophobic block (polystyrene). The AFM, SAXS and GISAXS studies realized on the MH-b-PS films showed that for this kind of copolymer whose one of the block is easily degraded withtemperature, the solvent annealing is more efficient than the thermal annealing to self-assemblethe copolymer. Then, an original study of the solvent annealing by QCM-D (Quartz crystalmicrobalance with dissipation monitoring) evidenced that this technique is able to characterize theviscoelasticity of the film and the amount of solvent absorbed by the copolymer during the solventtreatment. These useful measurements allowed to improve our understanding of the poorly knownsolvent annealing mechanism. To finish, we performed a study of the copolymer in solution and astudy of the impact of the chain length on the morphology of the film and were able to highlightthe specific behavior of this copolymer at the level of the polymer chain.

Des masques polymères à porosité contrôlée sont fabriqués à partir de films minces de copolymères à blocs auto-organisés polystyène-b-polylactide (PS-PLA) et polystyrène-b-poly(méthacrylate de méthyle) (PS-PMMA). Les films doivent être réorganisés grâce à une exposition aux vapeurs de solvant (THF ou DCE) pour obtenir des cylindres perpendiculaires à la surface, dans le volume et arrangés de façon hexagonale à longue distance. L’extraction sélective des domaines minoritaires conduit alors à des films minces poreux de PS. La mise en place de nouvelles techniques de caractérisation (analyse des images AFM, analyse MEB de répliques de système poreux, ellipso-porosimétrie) a permis d’évaluer l’influence de nombreux paramètres (nature du substrat, épaisseur du film, mode de dépôt, nature du solvant, temps et mode d’exposition aux vapeurs du solvant, …) sur la morphologie des films (surface, interface substrat/film, volume) et sur la cinétique de réorganisation. Des mélanges de copolymères à blocs A-B et d’homopolymères C (PS-PMMA/PLA, PS-PLA/PMMA, PS-PLA/PEO, PS-PEO/PLA, PS-PEO/PMMA, PS-PMMA/PEO) sont également étudiés. L’ajout d’homopolymères permet dans certains cas, d’améliorer la réorganisation des films de copolymères à blocs. Il permet également une augmentation des tailles caractéristiques du système. L’homopolymère C se localise au centre des domaines du bloc minoritaire B si χA-C> χB-C et χA-C > χA-B. Par exemple, dans le cas du mélange PS-PMMA/PLA, des cylindres perpendiculaires à la surface et organisés de façon hexagonale sont observés après exposition aux vapeurs de THF avec incorporation des domaines d’homopolymères PLA au centre des domaines de PMMA. / Polymer films with controlled porosity are obtained from block copolymer thin films of polystyrene-b-polylactide (PS-PLA) and polystyrene-b-poly(methylmethacrylate) (PS-PMMA). The morphology of these films must be reorganized by solvent annealing (THF or DCE) in order to obtain the cylinders perpendicular to the surface, in the volume and arranged in a hexagonal lattice over a long distance. The selective removal of the minority domains leads to a porous thin film of PS. New characterization techniques (AFM image analysis, SEM analysis of the silica replica, ellipsoporosimetry) are developed to evaluate the influence of various parameters (substrate nature, film thickness, method of deposition, duration and method of solvent vapors annealing …) on the morphology of the film (surface, interface and volume) and on the kinetics of reorganization. Blends of copolymer/homopolymer A-B/C (PS-PMMA/PLA, PS-PLA/PMMA, PS-PLA/PEO, PS-PEO/PLA, PS-PEO/PMMA, PS-PMMA/PEO) are also studied. In some cases, the addition of homopolymers can improve the reorganization of block copolymer films. It also allows an increase of the characteristics size of the system. Homopolymers C locate at the center of the minority B domains if χA-C> χB-C and χA-C> χA-B. For example, in the case of PS-PMMA/PLA blends, cylinders perpendicular to the surface and hexagonally arranged are observed after exposure to vapor of THF with incorporation of PLA homopolymer in central PMMA domains.