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Some of the major obstacles the microfluidics industry has yet to overcome in order to facilitate large scale manufacturing of devices are costly back-end processes. Among these, bonding presents some of the most obvious difficulties and is often associated with structural deformation and surface modification. Off-stoichiometric thiol-ene (OSTE) is a relatively new material and hasn’t yet achieved the same level of adoption as Polydimethylsiloxane (PDMS) which has been the go-to material in the field of microfluidics for over two decades. OSTE offers an alternative to PDMS and promises bonding without surface treatment as well as a hydrophilic surface, removing a step in the manufacturing process. In this work, the property of OSTE to bond with a variety of commonly used thermoplastic materials were tested as well as its suitability for use in pharmaceutical devices such as Lab-on-a-chip. In addition to untreated OSTE, a surface modifier was used to examine the potential for surface modification when using OSTE as a microfluidics material. From the testing performed, we demonstrated OSTE’s capacity to form robust bonds with a range of thermoplastic materials as well as comparable biocompatibility to PDMS. / Bland de största hindren som industrin ännu ej löst när det kommer till storskalig produktion av mikrofluidiska produkter är kostsamma ”back-end” processer. Av dessa presenterar bindingsprocesser några av de mest uppenbara svårigheterna och medför ofta deformationer av finstrukturer samt ändringar i ytkemi. Off-stoichiometric thiolene (OSTE) är ett relativt nytt material och har ännu inte blivit lika utbrett i sin använding som Polydimethylsiloxane (PDMS) vilket har varit standardmaterialet i mikrofluidik i över två årtionden. OSTE erbjuder ett alternativ till PDMS, med bindingsprocesser som ej kräver ytterligare ytmodifikationer och en hydrofil yta, vilket eliminerar ett steg i tillverkningsprocessen. I detta arbete undersöktes egenskapen av OSTE att binda till en rad ofta använda thermoplaster samt dess lämplighet i medicinskt bruk, i system som ”Lab-on-a-chip”. Förutom obehandlad OSTE, så användes en ytmodifierare för att undersöka möjligheten för ytmodifiering vid användingen av OSTE i mikrofluidik. Resultaten av våra tester visade OSTE’s förmåga att forma robusta bindingar till en rad thermoplaster så väl som en jämförbar biokompatibilitet till PDMS.

Diffusion of liquids into and through polymers is an important factor that negatively may influence the durability or lifetime of a polymer structure used in industrial applications. In this work two types of polymers, a liquid crystalline polymer (LCP, Vectra A950) and various thermoset resins as used in fibre reinforced plastics (FRP) process equipment were studied with regard to barrier properties, chemical resistance and long-term performance. LCP are known for their outstanding chemical resistance and barrier properties. FRP used in process equipment may be a cost-efficient solution in chemically aggressive environments where standard carbon or stainless steel cannot be used due to its limited corrosion resistance. Transport properties of typical industrial environments were determined for the LCP and the influence of annealing and orientation was investigated to study whether the barrier properties can be improved. The possibility to use LCP as cost-effective lining for FRP was explored. Special focus was put on the diffusion of water and its effect on long-term transport properties and stability of thermoset resins as the performance of FRP is strongly related to the diffusion of water. The results showed that Vectra A950 was suitable for organic solvent and non-oxidising acid environments. Its transport properties were gravimetrically determined and found to be 10 to 102 times lower than that of a high barrier fluoropolymer of type FEP. The degree of molecular packing increased with annealing time both below and above the melting point. Below the melting point this was – at least – partly due to crystal formation whereas above the melting point other mechanisms were involved. The effects of annealing and orientation on the transport properties in LCP were, however, very small or not significant and probably significantly longer annealing times are required. LCP has potential to be used as lining material for FRP as the use of an LCP-lining substantially reduced the permeability of and the solute sorption in a bisphenol A epoxy-based vinyl ester resin. The bonding strength was improved significantly by a combined abrasive and oxygen plasma treatment. The long-term sorption of water in thermoset resins including bisphenol A epoxy-based vinyl ester, novolac-based vinyl ester, urethane modified vinyl ester and bisphenol A polyester resins was found to increase with exposure time whereas the diffusion coefficient was not significantly affected. It was shown that the presence of water induced relaxation processes that were considered to be the primarily reason for the increase in sorption coefficient in comparison to degradation processes, such as hydrolysis, causing osmotic processes. A general relationship for the estimation of the sorption coefficient at 80ºC in dependence of the water activity and the sorption coefficient at unit activity independent of the resin type was established.

The future of aerospace has long been dedicated to making airplanes more lightweight and faster than ever before. Automation is essential to achieve these goals while maintaining a standard of consistency and quality. The overall goal of this research is to develop an automated piece of equipment that can effectively laminate a contoured composite layup at a rapid pace in order to compete with alternative options. In this study, the equipment and its components were designed and first evaluated through computational modeling and simulation. Then a prototype of the developed equipment was built for experimental testing and validating. The manufactured equipment was applied to form laminate sheets with different contours, ramp rates, and thicknesses. The forming speed and quality of the formed laminate sheets were assessed to validate the developed equipment.

La cellulose et le poly(éthylène 2,5-furandicarboxylate) (PEF) sont les deux précurseurs polymériques biosourcés étudiés dans ce travail de thèse. Deux approches ont été envisagées ; l’une se concentrant sur les aspects fondamentaux et l’autre sur l’élaboration de composites à partir de ces polymères. D’une part, la transition vitreuse et la cristallisation non-isotherme du PEF ont été explorées. Une approche cinétique de ces transitions a mis en lumière un comportement particulier du PEF et permet ainsi de mieux appréhender sa mise forme. De plus, la transition haute température de la cellulose Iβ a été étudiée pour la première fois en corroborant des techniques d’analyse thermiques et spectroscopiques complémentaires. En deuxième lieu, l’oxydation contrôlée d’une seule source de cellulose sous l’action du periodate de sodium a permis l’élaboration de composites entièrement cellulosiques qui se démarquent par leur haute performance mécanique. Enfin, le PEF et des nanocristaux de cellulose ont été combinés ce qui a permis l’élaboration de composites thermoplastiques où les cristaux de cellulose semblent jouer le rôle d’agents nucléants. / The cellulose and the poly(ethylene 2,5-furandicarboxylate) (PEF) were the two main biobased polymeric precursors employed in this thesis work. Two complementary investigation pathways were explored which respectively focus on the fundamental aspects and on elaboration of composites from these precursors. First, the glass transition and both the melt/glass non-isothermal crystallization of PEF were investigated. A kinetic approach of these transitions revealed a peculiar behavior of PEF which is useful to better understand its processing. In addition, the high-temperature transition of cellulose Iβ was for the first time explored by means of complementary thermo-analytical and spectroscopic techniques. On the other hand, the controlled periodate oxidation of one single cellulose source was employed to generate thermoset-like “all-cellulose composites” marked by their high mechanical performances. Finally, combination of PEF and cellulose nanocrystals allows to obtain transparent thermoplastic composites in which the cellulosic entities might have nucleating effects.

Le procédé du rotomoulage réactif est une technologie de fabrication de pièces creuses de taille et géométrie très variés. Une compréhension et une modélisation des phénomènes physiques qui interviennent dans les différentes étapes de la fabrication apportent une contribution importante à la maîtrise de ce procédé. Les travaux abordés dans cette thèse se situent dans le cadre d'un programme plus général visant le contrôle et le pilotage du rotomoulage réactif.Tout d'abord, une caractérisation et modélisation de la cinétique du polyuréthane thermodurcissable en mode dynamique est réalisé suivie par des mesures rhéologiques afin d'établir des lois rhéocinétique ainsi que des lois du comportement viscoélastiques du système réactionnel. Ces lois de comportement sont établies conformément aux conditions réelles de la mise en œuvre du matériau.Ensuite, nous simulons le procédé du rotomoulage en utilisant un code de calcul basé sur la méthode « Smoothed Particle Hydrodynamics » (SPH), développé par notre équipe, en implémentant des nouveaux paramètres physiques: le caractère non-newtonien du mélange réactionnel et les effets de tension superficielle.Le modèle de tension de surface en 2 et 3D développé dans cette thèse permet la détection explicite de l'interface séparant le fluide réactif de l'air. Puis, nous utilisons l'interpolation lagrangienne ou la régression circulaire pour construire la courbe d'interface en 2D et la surface d'interface en 3D sera reconstruite via la régression sphérique. Quant à la modélisation de l'écoulement du fluide non-newtonien, une loi de puissance décrivant l'évolution de la viscosité en fonction du taux de cisaillement a été intégrée dans le solveur pour décrire le caractère non-newtonien du mélange réactionnel durant sa mise en œuvre. Ces paramètres physiques implémentés dans le code ont été validé par une série de cas de tests en 2 et 3D.L'intégration des effets de tension de surface et la prise en compte du caractère non-newtonien du fluide réactif nous ont permis de mieux présenter la mouillabilité de la surface interne du moule et l'étalement des différentes couches du polymères.Mots clés : rotomoulage réactif, polyuréthane thermodurcissable, rhéocinétique, Smoothed Particle Hydrodynamics, tension de surface, fluide non-newtonien, simulation. / Reactive Rotational molding (RRM) is a process for manufacturing hollow plastic products with no weld lines, in virtually any shape, size, color and configuration, using biaxial rotation and high temperature. Understanding and modelling of physical phenomena provide a great contribution for process control that is the purpose of a more general program.Firstly, a characterization and the kinetic modeling of the thermoset polyurethane are performed in anisothermal conditions followed by rheological measurements in order to establish rheokinetik model and the the viscoelastic behavior of the reactive system according with RRM conditions.Afterwards, to simulate the RRM, Smoothed Particles Hydrodynamics (SPH) method is applied which is suited method to simulate the fluid flow with free surface such as occurs at RRM. This solver is developed by our team. Modelling and simulating reactive system flow depend on different parameters; the physical phenomena involved are: surface tension force and non-newtonian fluid behavior.The surface tension method has been successfully applied to simulate RRM using SPH solver taking into account free surface tension force. Surface tension force is given explicitly in the current model. After detecting the boundary particles, the interface is locally fitted by using Lagrangian interpolation polynomial or fitting circle in 2D and by using fitting sphere in 3D, respectively. To study the non-newtonian fluid flow during RRM, a power law describes the evolution of the viscosity versus shear rate was adopted to describe the viscoelastic nature of the reactive fluid during its shaping.The implementation of surface tension and viscoelasticity allows us to present the wettability of internal surface of the mold and the spreading of different polymers layers.Keywords : Reactive rotational molding, thermoset polyurethane, rheokinetik, Smoothed Particle Hydrodynamics, surface tension, non-newtonian fluid, simulation.

Os compósitos são materiais formados por duas fases de diferentes propriedades químicas e físicas, sendo uma matriz e um reforço, que apresentam alta rigidez, melhores respostas à fadiga sob cargas cíclicas, leveza e resistência mecânica, o que os torna viáveis para substituir materiais nobres e de custo elevado, com diversas aplicações na aeronáutica, nos esportes, na indústria bélica e principalmente na construção civil. Além disso, os compósitos podem ser obtidos a partir da incorporação de resíduos em sua composição, solucionando problemas como o descarte irregular. Com o intuito de contribuir nessa área de conhecimento o presente estudo propôs o desenvolvimento de um compósito em forma de placas poliméricas a partir da incorporação do agregado reciclado de poliuretana termofixa reciclado à resina vegetal de mamona e à mantas de fibra de vidro. Para isso, o trabalho estabeleceu uma metodologia na qual o resíduo industrial de poliuretana termofixa é transformado em agregado reciclado, a partir de processos de corte e moagem, caracterização e classificação segundo as normas NBR 10.004 a 10.007 (ABNT, 2004). Na sequência, com o auxílio de uma prensa térmica, foi possível confeccionar as placas poliméricas e caracterizálas quanto às suas propriedades mecânicas (tração, flexão, punção), físicas (absorção em água, inchamento, densidade e dureza), térmicas (condutividade térmica) e quanto ao seu potencial de durabilidade (resistência ao impacto, à abrasão superficial, ao ataque químico, à exposição ao ultravioleta e às intempéries, resistividade elétrica e flamabilidade). Os resultados obtidos por meio dos ensaios realizados apontaram que os parâmetros ensaiados comportaram-se como materiais semelhantes àqueles utilizados na construção civil, o que possibilita a utilização do material desenvolvido nesta pesquisa em aplicações por este setor. / This study proposes the development of a composite material in the form of polymer slabs. The material is created from the incorporation of recycled thermoset polyurethane to castor oil resin and glass fiber mats. Composite materials are formed by two phases with different chemical and physical properties. One phase is a matrix, and the other a reinforcement. These materials are highly stiff, light, have mechanical strength and present better responses to fatigue under cyclic loads. These properties make them a substitute for noble materials, being eligible for uses in aviation, sports, the arms industry and, specially, civil construction. Furthermore, composites may be obtained by the incorporation of residue, solving problems of waste disposal. In the procedures undertaken, the industrial waste of thermoset polyurethane is transformed into a recycled aggregate, achieved by the cutting, grinding, characterization and classification in compliance to the ABNT standards (NBR 10.004 to10.007). Afterwards, with the use of a thermal press, it was possible to produce the slabs and characterize them according to the following properties: mechanical (tensile strength, and puncture), physical (water absorption, swelling and stiffness), thermal (conductivity) and the potential durability (resistance to impact, abrasion, chemical attack. ultraviolet and weather exposure, electrical resistance, and flammability). The test results indicated that the composite behaves similarly to materials used in civil construction, which enables its use in the area.

Les travaux présentés dans ce manuscrit sont consacrés à l’étude et à l’élaboration de résines de collage bio-sourcées pour remplacer les résines Urée-Formol (UF) d’origine pétrochimique, sources de formaldéhyde, utilisées actuellement dans l’industrie panneautière. Les résines étudiées dans le cadre de cette thèse sont formulées à partir de ressources locales (dextrines issues d’amidon de maïs et tanins d’écorces de pin maritime) et doivent respecter certaines contraintes industrielles. Pour répondre à ces contraintes, les travaux de recherche présentés dans ce mémoire vont de la compréhension structurale des mélanges des produits de base jusqu’à la fabrication de panneaux à l’échelle du laboratoire, en passant par la formulation et la réticulation des différentes résines thermodurcissables. Ces travaux montrent qu’il est nécessaire de travailler en milieu alcalin pour solubiliser les tanins. Dans cette situation, les mélanges tanins/dextrines donnent des suspensions colloïdales. Les fractions massiques en tanins et en dextrines permettant d’obtenir des paramètres respectant le cahier des charges varient de 0 à 40%. La réticulation de ces mélanges par l’épichlorhydrine a permis l’obtention de colles thermodurcissables insolubles dans l’eau ayant une bonne stabilité dimensionnelle à sec, mais un pouvoir gonflant plus ou moins important selon la formulation. Les propriétés adhésives, mécaniques et thermiques de ces matériaux ont été caractérisées et ont permis de sélectionner des formulations de colles ayant les meilleures performances thermomécaniques. Enfin, tout en respectant un protocole industriel, des composites ont été fabriqués à partir de ces colles et des particules de bois. Il a été montré que les panneaux de particules obtenus ont des performances mécaniques équivalentes à ceux fabriqués avec des colles UF. / This work aims to substitute resins based on formaldehyde as UF by “green” thermosetting adhesives based on natural and renewable local products, in the wood composite industry. The resins studied in this thesis are made from local resources (dextrins from corn starch and tannins from maritime pine barks) and must respect certain industrial requirements. To meet these industrial constraints, the research work of this manuscript deals with studies ranging from the structural understanding of basic product mixtures, up to the characterization of the properties of panels manufactured in the lab, including the formulation and reticulation of resins. These studies show that it is necessary to work in an alkaline medium to solubilize the tannins. In this situation, the tannins / dextrin mixtures give colloidal suspensions. The mass fractions in tannins and dextrins allowing to obtain parameters respecting the specifications vary from 0 to 40%. The epichlorohydrin has been used as hardener to cross-link these resins. Thermosetting materials with good dimensional stability have been obtained. However the resin swelling depends on the composition of the formulation. Adhesive, mechanical and thermal properties of these materials were characterized. Thus, adhesive formulations with the best thermomechanical performances have been selected. Finally, composites have been made from these adhesives and wood particles, respecting an industrial procedure. It has been shown that these panels and those obtained with UF adhesives have equivalent mechanical performances.

nÃo hà / à crescente o interesse mundial pelo desenvolvimento de tecnologias chamadas âverdesâ que possibilitem o uso de produtos com menor impacto ao meio ambiente, assim como tambÃm se fortalecem as polÃticas de incentivo ao aproveitamento mÃximo e sustentÃvel dos recursos naturais. O principal objetivo desse estudo foi desenvolver nanobiocompÃsitos superparamagnÃticos para aplicaÃÃo como antenas ressoadoras dielÃtricas. Para tal, um plÃstico termorrÃgido biobaseado foi preparado utilizando o cardanol em alternativa aos fenÃis petroquÃmicos. Esse plÃstico termorrÃgido foi utilizado como matriz para o preparo de biocompÃsitos, utilizando 15% em massa de fibra de bucha bruta e tambÃm modificada por tratamento quÃmico (NaOH 5, 10 e 15% e NaClO 1%) como fase dispersa. Para o preparo dos nanobiocompÃsitos, alÃm da fibra de bucha, nanopartÃculas de magnetita, sintetizadas pelo mÃtodo da coprecipitaÃÃo, foram impregnadas no plÃstico termorrÃgido em diferentes teores de 1, 5 e 10% em massa. TÃcnicas de Termogravimetria (TG), Calorimetria exploratÃria diferencial (DSC), AnÃlise dinÃmico-mecÃnica (DMA), Microscopia eletrÃnica de varredura (MEV), Microscopia Ãptica, Microscopia eletrÃnica de transmissÃo (MET), DifraÃÃo de raios X (DRX), Espectroscopia no infravermelho com transformada de Fourier (FTIR), Espectroscopia MÃssbauer, Ensaios de resistÃncia à traÃÃo, Medidas dielÃtricas, Magnetometria de amostra vibrante (VSM) e BiodegradaÃÃo em solo simulado foram utilizadas para caracterizaÃÃo. Os resultados mostraram que o tratamento alcalino melhorou a estabilidade tÃrmica e o Ãndice de cristalinidade da fibra de bucha. O agente reticulador utilizado (DETA) mostrou-se eficiente, possibilitando a cura completa dos materiais. Os biocompÃsitos com fibra tratada apresentaram maior estabilidade tÃrmica, resistÃncia à traÃÃo superior e melhor Ãndice de biodegradaÃÃo em relaÃÃo ao biocompÃsito com fibra natural. A magnetita sintetizada exibiu tamanho nanomÃtrico, alÃm de alta pureza, alta cristalinidade e carÃter superparamagnÃtico. Todos os nanobiocompÃsitos exibiram superparamagnetismo e mostraram excelente estabilidade tÃrmica, boas taxas de biodegradaÃÃo e melhor resistÃncia mecÃnica para o material com 10% de magnetita. Todas as antenas ressoadoras dielÃtricas preparadas apresentaram perda de retorno satisfatÃria e, portanto, adequaÃÃo para fins comerciais e tecnolÃgicos, com maior potencial para atuaÃÃo em banda larga. / There is a growing global interest for the development of green technologies that allow the use of products with less damage to environment, as well as for maximum and sustainable use of natural resources. The main aim of this study was to develop superparamagnetic nanobiocomposites for application as dielectric resonator antennas. For this purpose, a biobased thermoset plastic was prepared by using cardanol as an alternative to petrochemical phenol. This thermoset plastic was used as a polymer matrix and biocomposites were prepared by using 15 wt% of untreated and modified sponge gourd fibers by chemical treatment (NaOH 5, 10, and 15 wt% and NaClO 1 wt%) as dispersed phase. For the nanobiocomposites preparation, besides the sponge gourd fibers insertion, the thermoset plastic were also impregnated with magnetite nanoparticles in different contents (1, 5, and 10 wt%). Techniques of Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), Optical Microscopy, Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), MÃssbauer Spectroscopy, Tensile testing, Dielectric measurements, Vibrating Sample Magnetometry (VSM) and Biodegradation in simulated soil were performed for characterization. The results showed that alkaline treatment improved the thermal stability and the crystallinity index of the sponge gourd fiber. The crosslinking agent used (Diethylenetriamine) was efficient and enabled complete cure for all materials. The biocomposites reinforced by treated fiber showed better thermal stability, superior performance in Tensile testing and greater biodegradation rates, when compared to the biocomposite reinforced by raw fiber. The magnetite particles exhibited nanometric size, high purity and crystallinity, and superparamagnetic character. All nanobiocomposites showed superparamagnetic behavior, excellent thermal stability, good biodegradation rates, and better mechanical strength for the material with magnetite 10 wt%. All dielectric resonators antennas exhibited satisfactory return loss and suitability for commercial and technological applications, especially for performance in broadband.

Os compósitos são materiais formados por duas fases de diferentes propriedades químicas e físicas, sendo uma matriz e um reforço, que apresentam alta rigidez, melhores respostas à fadiga sob cargas cíclicas, leveza e resistência mecânica, o que os torna viáveis para substituir materiais nobres e de custo elevado, com diversas aplicações na aeronáutica, nos esportes, na indústria bélica e principalmente na construção civil. Além disso, os compósitos podem ser obtidos a partir da incorporação de resíduos em sua composição, solucionando problemas como o descarte irregular. Com o intuito de contribuir nessa área de conhecimento o presente estudo propôs o desenvolvimento de um compósito em forma de placas poliméricas a partir da incorporação do agregado reciclado de poliuretana termofixa reciclado à resina vegetal de mamona e à mantas de fibra de vidro. Para isso, o trabalho estabeleceu uma metodologia na qual o resíduo industrial de poliuretana termofixa é transformado em agregado reciclado, a partir de processos de corte e moagem, caracterização e classificação segundo as normas NBR 10.004 a 10.007 (ABNT, 2004). Na sequência, com o auxílio de uma prensa térmica, foi possível confeccionar as placas poliméricas e caracterizálas quanto às suas propriedades mecânicas (tração, flexão, punção), físicas (absorção em água, inchamento, densidade e dureza), térmicas (condutividade térmica) e quanto ao seu potencial de durabilidade (resistência ao impacto, à abrasão superficial, ao ataque químico, à exposição ao ultravioleta e às intempéries, resistividade elétrica e flamabilidade). Os resultados obtidos por meio dos ensaios realizados apontaram que os parâmetros ensaiados comportaram-se como materiais semelhantes àqueles utilizados na construção civil, o que possibilita a utilização do material desenvolvido nesta pesquisa em aplicações por este setor. / This study proposes the development of a composite material in the form of polymer slabs. The material is created from the incorporation of recycled thermoset polyurethane to castor oil resin and glass fiber mats. Composite materials are formed by two phases with different chemical and physical properties. One phase is a matrix, and the other a reinforcement. These materials are highly stiff, light, have mechanical strength and present better responses to fatigue under cyclic loads. These properties make them a substitute for noble materials, being eligible for uses in aviation, sports, the arms industry and, specially, civil construction. Furthermore, composites may be obtained by the incorporation of residue, solving problems of waste disposal. In the procedures undertaken, the industrial waste of thermoset polyurethane is transformed into a recycled aggregate, achieved by the cutting, grinding, characterization and classification in compliance to the ABNT standards (NBR 10.004 to10.007). Afterwards, with the use of a thermal press, it was possible to produce the slabs and characterize them according to the following properties: mechanical (tensile strength, and puncture), physical (water absorption, swelling and stiffness), thermal (conductivity) and the potential durability (resistance to impact, abrasion, chemical attack. ultraviolet and weather exposure, electrical resistance, and flammability). The test results indicated that the composite behaves similarly to materials used in civil construction, which enables its use in the area.