Orientador: João Sinezio de Carvalho Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-14T21:10:09Z (GMT). No. of bitstreams: 1 Costa_NelsonRodrigo_M.pdf: 6493019 bytes, checksum: f667f5f51dcc90a9fe8da70609bb259d (MD5) Previous issue date: 2009 / Resumo: A proposta deste trabalho é desenvolver um material de fácil processamento de é boa condutividade elétrica. O método de preparação escolhido foi o de solução dos polímeros escolhidos, PAni dopada com ADBS e do copolímero de etileno/propileno, num solvente comum (Xileno) com a subseqüente evaporação total do solvente. Caracterizou-se os efeitos da PAni/ADBS (10%, 20%, 40% e 50%), do EPR e do anidrido maléico (MAH) juntamente com o peróxido como compatibilizantes. A análise termogravimétrica mostra que as blendas desenvolvidas apresentam três fases de perda de massa, sendo a segunda a principal. O ADBS degrada no segundo estágio e por conseqüência desdopa a PAni. Além disto, revela que as blendas com 50% de PAni apresentam uma temperatura de degradação ao redor de 335 ºC, a qual é superior ao polímero puro (295ºC). Isto leva à suposição de uma parcial compatibilização do EPR com a PAni/ADBS. A hipótese volta a ser sustentada pela análise de DSC, onde a Tg é influência pela concentração de EPR. As blendas apresentam mais de uma Tg, apontando para a imiscibilidade, mas a Tg da fase rica em PAni/ADBS da blenda com 20% de PAni/ADBS é de 65ºC, enquanto que na blenda com 50% é de 54ºC, o que levanta a suposição de uma miscibilidade parcial. O MAH e o peróxido não influenciaram nos resultados das análises térmicas. Ao passo que, a técnica analítica de infravermelho não identificou mudanças vibracionais nas moléculas das blendas em estudo, não suportando a hipótese de miscibilidade mesma que parcial. As imagens de MEV mostram uma blenda imiscível e uma estrutura de placas que evolui com o aumento da concentração de PAni/ADBS. Nota-se também uma evolução diferenciada da fase PAni/ADBS nas blendas com MAH e peróxido, levando a uma hipótese que estes compostos devem influenciar na morfologia da fase PAni/ADBS. A avaliação da condutividade elétrica superficial das blendas mostra que ela é proporcional à concentração da PAni/ADBS e que as blendas com 50% de PANi/ADBS apresentam apenas uma década de diferença de condutividade em relação a PAni/ADBS pura. Com base nos resultados obtidos o processamento via solução mostra ser um método promissor, proporcionando blendas de alta estabilidade térmica e boa condutividade. / Abstract: The proposal of this work is to develop a new material, which is easy to process and it has a good electrical conductivity. The process method chosen was the solution of the polymers, doped polyaniline with dodecilbenzeno sulfonic acid and the ethylene/propylene copolymer, in a common solvent (Xylene), follow by casting. The effect of PAni/ADBS (10%, 20%, 40% and 50%), EPR, maleic anhydride and peroxide were characterized. The thermo gravimetric analyses showed that the blends have three steps of mass loss, among them the second is the more important. The DBSA degrades in the second step, consequently, desdopes the PAni. Besides, the TGA pointed out that the blend with 50% of PAni/DBSA has a temperature of degradation around 3350C, which is higher than the PAni/DBSA polymer (2950C). Based on that, the hypothesis of partial compatibilization between EPR and PAni/DBSA was raised. The DSC analyses supported this assumption (the Tg is influenced by EPR concentration). The blends have more than one Tg, indicanting that the blends are immiscible, but the Tg of the PAni/DBSA phase with 20% of PAni/DBSA is 650C, while the blend with 50% is 540C. The MAH and the peroxide did not influence the results of the thermo analyses. Regards to infrared spectroscopy analyses, the technique did not identify any change in the vibrations of molecule of the developed blends, thence it follows that the miscibility hypothesis, even partial, is not supported by infrared. The SEM photographs showed more than one phase and plates structures. These plates structures are influenced by the MAH and by the peroxide. Perhaps, these substances influence the morphology of PAni/DBSA phase. The superficial electrical conductivity of the blends is proportional to PAni/DBSA concentration and the blends with 50% of PAni/DBSA have only one decade of difference in relation to PAni/DBSA polymer. / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química

HASEL-actuators use dielectric liquids and compliant shells as their media. This type of actuatorwould suit the actuators used as fins for soft milli robots (SOMIRO). These robots are going tobe used in aquaponic crops for studying its impact on the environment to help the farmersimprove their crops. The robots have to be soft and compliant, so the materials used for theHASEL-actuator should have the same properties. First, an automatic manufacturing method isinvestigated to find a proper way to produce these actuators. It was concluded that a processcalled the “two-layered actuator” had the most potential, where a PU film, PET film andDUALBOND glue was used to produce a well-defined HASEL-actuator by creating a cavitywithin the PU film by using a suction flask and fill the cavity with coconut oil. The cavity'sshape was two domes (3 mm in diameter) connected with a middle channel (1 mm in diameterand a length of 3 mm). The actuator had electrodes made of a curable silver paste or Galinstanwhere their potential difference is used for powering the actuation. The aim for the neededvoltage when actuating the actuators was to be below 1kV. This means that the actuators have tobe as thin and have a low Young’s modulus as possible. The silver electrodes made the actuatortoo stiff to actuate at that low voltage, so the other potential materials would be Galinstan as theelectrode and PDMS and PU film which could replace the PU and PET respectively. Dependingon the pressure used on the suction flask for fabrication of the two-layered actuator, differentheights of the cavity could be achieved. By changing the pressure to 1 kPa, it was found out thatthe lowest height of 260 µm could be achieved. Different compositions of paraffin oils wereevaluated to find a suitable dielectric liquid with the right melting temperature since the actuatoronly works when the media is in its liquid state. The sample showing highest potential had amixture of 4.4 g of a liquid paraffin oil and 1.17 g of a soft paraffin wax. The starting meltingpoint was concluded to be at 5 °C. During the voltage test of the actuators, no sign of movementcould be seen for any of the produced actuators when reaching the highest voltage of 1 kV. Thisindicates that the actuators are still too thick and stiff and needs to be improved in the future

The thesis presents a method of evaluation for blade damage in Combustion Turbine Compressor Section. This method involves use of multiple domains within a single Finite Element Model to predict the effect of damage on the blade properties. This approach offers significant time and effort savings when compared to traditional evaluation methods of similar problems. It is demonstrated via examples that the multi-domain modeling approach yields acceptable accuracy results. The economical implications of described method are readily applicable to both the industrial and the aerospace Combustion Turbine fields. It is economically impractical to replace the blade at each damage occurrence. However, the evaluation time involved in making associated decisions can be extensive if traditional methods of evaluation are used. The specific contributions of this study are twofold: 1. Time savings during evaluation 2. Compressor Blades may be returned to service which are otherwise replaced

The fundamental requirement for a coal preparation plant is to transform low value run-of-mine (ROM) material into high value marketable products. The significant aspect relative to the plant is that any gain in efficiency flows almost entirely to the "bottom line" for the operation. The incremental quality concept has gained wide acceptance as the best method to optimize the overall efficiency of the various cleaning circuits. Simply stated, the concept requires that all the cleaning circuits operate as near as possible to the same incremental quality. To ensure optimal efficiency, a plant that receives ROM feed from multiple sources must develop a strategy to operate at the same incremental quality, which yields wide ranges in product qualities from the individual ROM coals. In order to provide products that meet contract specifications, clean coal stockpiles can be utilized to accept coals with various qualities, such as "premium," "low," and "filler" qualities, with shipments formulated from the stockpiles to meet product specifications. A more favorable alternative is raw coal blending to produce the specified clean coal qualities. This study will review the incremental quality concept and present case studies in applying the concept to meet product specifications. / Master of Science

<P> Responsive polymer composites were developed by incorporating a functional component into a nonpolar amorphous polymer. The response of the polymer composite is the change in color observed upon exposing the composite to different acids. One application could be a device to monitor the diffusion of different acids in different polymers. </p> <p> The research contained within this thesis deals with an investigation of basic properties of polymer composites. This was accomplished, first through the preparation of a composite of phenolphthalein disodium and Linear Low Density Polyethylene (LLDPE), second, by monitoring the decolorizing process and the aspects that affect it. The investigations included the extrusion parameters, types of acid, acid concentration and indicator concentration, and lastly by quantifying the process through the comparison of empricial diffusion coefficients and corresponding diffusion rates. </p> <p> This study has shown that decolorization occurs at a fast pace in the presence of acetic acid and slow in the presence of hydrochloric acid. Further as the indicator concentration increases, the decolorization process becomes slower. Techniques used to monitor the properties were Scanning Electron Microscopy (SEM) micrographs of freeze fractured composites, Differential Scanning Calorimetry (DSC) scans for the starting materials as well as the composites, and photography of the cross-sections of sample composite cylinders. </p> / Thesis / Master of Science (MSc)

Due to the wide range of properties of plastics (e.g. low density), more and more conventional materials are substituted by polymer materials. Complex requirement profiles on technical parts increase the demand for joining processes that enable the reliable joining of otherwise incompatible thermoplastics. In this case, material bonded connections are approaching their limits. In the following study two incompatible thermoplastic polymers were welded by using polymer blends that are compatible to both components. Industrially relevant thermoplastics polyethylene (PE) and polyamide 12 (PA12) were chosen to demonstrate the potential of an innovative joining technology.

In this paper I use the Distributional Morphology framework and semantic Locality Constraints proposed by Arad (2003) to look at category assignments of blends in Modern Hebrew, as well as blends, compounds and idioms in English where relevant. Bat-El (1996) provides an explicit phonological analysis of Modern Hebrew blends, and argues against any morphological process at play in blend formation. I argue, however, that blends and compounds must be accounted for within morphology due to category assignments. I first demonstrate that blends are unquestionably formed by blending fully inflected words rather than roots, and then subsequently reject an analysis that accounts for weakened Locality Constraints by proposing the formation of a new root. Instead, I propose a hypothesis of Idiomatic Root Merge where a root can be an n-place predicate that selects at least an XP sister and a category head. This proposal also entails that there is a structural difference between two surface-similar phrases that have respectively literal and idiomatic meanings.

As blendas poliméricas são importante alternativa ao mercado para se conseguir de forma economicamente vantajosa ou sob o ponto de vista de processabilidade produtos com propriedades otimizadas para aplicações específicas. Blendas com razões de composição variadas entre diferentes polímeros atendem aplicações muitas vezes com requisitos intermediários entre materiais. Este trabalho revisa sucintamente a literatura sobre blendas poliméricas, a produção em laboratório de uma blenda mecânica de poli(cloreto de vinila) PVC e poli(metacrilato de metila) - PMMA, avalia as propriedades de blendas com frações variadas de PVC/PMMA e discute o potencial de aplicação no mercado. A blenda miscível caracterizada tem custo, resistência à chama e propriedades mecânicas e térmicas intermediárias aos dois polímeros puros. / Polymer blends are an important alternative in the market for achieving, in an economically and advantageous way or just considering processability products with optimized properties for specific applications. Blends with variable composition ratios, between two different polymers, fit to applications with intermediate requirements between two different materials. This paper reviews slightly the literature about polymer blends, the lab scale production of a mechanical blend of poli(vinylene vhloride) - PVC and poly(methyl metacrylate) - PMMA with different PVC/PMMA ratios and the application potential. The miscible blend shows intermediate cost, flame resistance, mechanical and thermal properties then those shown by its neat polymers.

As blendas poliméricas são importante alternativa ao mercado para se conseguir de forma economicamente vantajosa ou sob o ponto de vista de processabilidade produtos com propriedades otimizadas para aplicações específicas. Blendas com razões de composição variadas entre diferentes polímeros atendem aplicações muitas vezes com requisitos intermediários entre materiais. Este trabalho revisa sucintamente a literatura sobre blendas poliméricas, a produção em laboratório de uma blenda mecânica de poli(cloreto de vinila) PVC e poli(metacrilato de metila) - PMMA, avalia as propriedades de blendas com frações variadas de PVC/PMMA e discute o potencial de aplicação no mercado. A blenda miscível caracterizada tem custo, resistência à chama e propriedades mecânicas e térmicas intermediárias aos dois polímeros puros. / Polymer blends are an important alternative in the market for achieving, in an economically and advantageous way or just considering processability products with optimized properties for specific applications. Blends with variable composition ratios, between two different polymers, fit to applications with intermediate requirements between two different materials. This paper reviews slightly the literature about polymer blends, the lab scale production of a mechanical blend of poli(vinylene vhloride) - PVC and poly(methyl metacrylate) - PMMA with different PVC/PMMA ratios and the application potential. The miscible blend shows intermediate cost, flame resistance, mechanical and thermal properties then those shown by its neat polymers.

This thesis describes a fundamental study of the miscibility and the nature of the interface between components of core-shell polymer blends using the technique of Fluorescence Resonance Energy Transfer (FRET) coupled with data analysis that involves Monte-Carlo simulations. Our aim in this study was to develop a fundamental methodology to quantitatively determine the width of the interface between the two components in binary polymer blends. At the current state of the art, data analysis of FRET experiments requires translational symmetry. In the system under study, uniform core-shell structures satisfy this criterion. Thus, in this work our focus was directed toward the study of a blend system with a core-shell structure. For this FRET study, I have identified a number of potential donor and acceptor dye pairs that fluoresce in the visible range of the spectrum and can be chemically attached to polymers. Among them, I selected, as the donor and the acceptor, a pair of naphthalimide dyes that have not previously been used for FRET experiments. Model experiments showed that while the fluorescence decay profile of the donor chromophore was exponential in solution, it was not exponential in polystyrene (PS) or poly(methyl methacrylate) (PMMA) films. Thus, I carried out refinements to existing FRET theory to interpret the data generated by using these dyes. Also, I derived a new model to predict the fluorescence intensity of non-exponential decaying donor dyes in core-shell systems. I selected a model system composed of a PS core surrounded by a PMMA shell. The PS core particles were prepared by miniemulsion polymerization to obtain cross-linked PS particles with a narrow size distribution. Seeded emulsion polymerization under starved-fed condition was employed to synthesize monodisperse dye-labeled core-shell particles. The extent of miscibility and the nature of interface between the core and the shell polymers were retrieved from a combined study by Monte-Carlo simulations and analysis of the donor fluorescence intensity decays. Agreement between the retrieved interface thickness and the literature data on PS-PMMA validates the methodology developed here for the use of such donor dyes in FRET studies on polymer blends.