Droplet vaporization and combustion of biodiesel, diesel and their blends was examined experimentally in a turbulent flow at elevated ambient temperature and pressure conditions. A high pressure vessel capable of generating high levels of turbulence was employed in this study. The linear relationship between turbulence intensity and fans rotational speed, which was developed at room temperature, was found to be unaffected by the gas ambient temperature. Droplet vaporization experiments were performed by varying turbulence intensity (i.e., the fans rotational speed) from 0 up to 3.1 m/s, ambient temperature and pressure up to 473 K and 16 bar, respectively. The results revealed that diesel droplet vaporization did not follow the d2-law under the aforementioned test conditions. However, biodiesel droplet vaporization obeyed the d2-law. Droplet vaporization of the blends, i.e. B20 and B50, displayed a mixed behaviour of both parent fuels with the biodiesel behaviour predominating where biodiesel content slows down the droplet vaporization of the blends. Turbulence was found to reduce the droplet lifetime of all fuels (i.e., increases droplet vaporization rate), and its effect becomes more effective with increasing ambient pressure. Droplet combustion experiments were performed by varying turbulence intensity from 0 up to 1.20 m/s, and ambient temperature up to 423K at ambient pressure of 1 atm. Diesel droplet combustion rate showed negligible change with turbulence intensity up to 0.40 m/s beyond which the burning rate decreased slightly with turbulence intensity. Similarly, biodiesel droplet combustion rate did not show an increase with the presence of a turbulent flow around the droplet. However, in contrast to diesel, biodiesel burning rate remained nearly constant until the flame extinction limit. The combustion rate of B20 and B50 displayed a mixed behaviour of both parent fuels. Nevertheless, both blends showed that diesel had predominance over the burning rate. Finally, the droplet flame extinction of all fuel droplets occurred at turbulent velocity slightly greater than the laminar flame speed.

Droplet vaporization and combustion of biodiesel, diesel and their blends was examined experimentally in a turbulent flow at elevated ambient temperature and pressure conditions. A high pressure vessel capable of generating high levels of turbulence was employed in this study. The linear relationship between turbulence intensity and fans rotational speed, which was developed at room temperature, was found to be unaffected by the gas ambient temperature. Droplet vaporization experiments were performed by varying turbulence intensity (i.e., the fans rotational speed) from 0 up to 3.1 m/s, ambient temperature and pressure up to 473 K and 16 bar, respectively. The results revealed that diesel droplet vaporization did not follow the d2-law under the aforementioned test conditions. However, biodiesel droplet vaporization obeyed the d2-law. Droplet vaporization of the blends, i.e. B20 and B50, displayed a mixed behaviour of both parent fuels with the biodiesel behaviour predominating where biodiesel content slows down the droplet vaporization of the blends. Turbulence was found to reduce the droplet lifetime of all fuels (i.e., increases droplet vaporization rate), and its effect becomes more effective with increasing ambient pressure. Droplet combustion experiments were performed by varying turbulence intensity from 0 up to 1.20 m/s, and ambient temperature up to 423K at ambient pressure of 1 atm. Diesel droplet combustion rate showed negligible change with turbulence intensity up to 0.40 m/s beyond which the burning rate decreased slightly with turbulence intensity. Similarly, biodiesel droplet combustion rate did not show an increase with the presence of a turbulent flow around the droplet. However, in contrast to diesel, biodiesel burning rate remained nearly constant until the flame extinction limit. The combustion rate of B20 and B50 displayed a mixed behaviour of both parent fuels. Nevertheless, both blends showed that diesel had predominance over the burning rate. Finally, the droplet flame extinction of all fuel droplets occurred at turbulent velocity slightly greater than the laminar flame speed.

This investigation presents research on the characteristic properties of Nylon66 and poly(ethylene naphthalate) (Ny66/PEN), and poly(butylene terephthalate) and poly(ethylene naphthalate) (PBT/PEN) blends with several weight compositions made by melt blending, by the use of 13C and 1H Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and Dynamic mechanical thermal analysis (DMTA), X-ray diffraction (X-RD), tensile, impact and stress relaxation tests. Ny66/PEN blends including several additives do not improve the miscibility of the constituent polymers and show lower tensile strength than those of homopolymers. However, PBT/PEN blends reveal improved tensile strengths of the blends between the ROM and MROM predictions lines with more than 50 % volume fraction of PEN. On the other hand, NMR spectra show no evidence of interchange reaction in both Ny66/PEN and PBT/PEN blends. SEM micrographs of fracture surfaces in PBT/PEN blends reveal a very small (sub-micron) domain size in contrast to large domains in Ny66/PEN blends, which indicates partial miscibility of PBT and PEN. DSC and DMTA demonstrate partial miscibility of PBT/PEN blends by the change of Tgs of each component according to the weight proportions of the constituent polymers. Stress relaxation tests for the specimens of PBT/PEN blends and the homopolymers, using the Taguchi method of experimental design, determine that the most significant factor is the temperature, followed by PEN content and then the initial stress, and interaction effects between factors are insignificant. To fit the relaxation curves of the PBT/PEN blends and the homopolymers at different temperatures, PEN contents and initial stresses, four different equations have been used. The coefficients of the equation that fit best are used to predict the relaxation behaviour of PBT/PEN blends at a temperature between 30C and 60C, and at the initial stresses of 7 MPa.

This investigation presents research on the characteristic properties of Nylon66 and poly(ethylene naphthalate) (Ny66/PEN), and poly(butylene terephthalate) and poly(ethylene naphthalate) (PBT/PEN) blends with several weight compositions made by melt blending, by the use of 13C and 1H Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and Dynamic mechanical thermal analysis (DMTA), X-ray diffraction (X-RD), tensile, impact and stress relaxation tests. Ny66/PEN blends including several additives do not improve the miscibility of the constituent polymers and show lower tensile strength than those of homopolymers. However, PBT/PEN blends reveal improved tensile strengths of the blends between the ROM and MROM predictions lines with more than 50 % volume fraction of PEN. On the other hand, NMR spectra show no evidence of interchange reaction in both Ny66/PEN and PBT/PEN blends. SEM micrographs of fracture surfaces in PBT/PEN blends reveal a very small (sub-micron) domain size in contrast to large domains in Ny66/PEN blends, which indicates partial miscibility of PBT and PEN. DSC and DMTA demonstrate partial miscibility of PBT/PEN blends by the change of Tgs of each component according to the weight proportions of the constituent polymers. Stress relaxation tests for the specimens of PBT/PEN blends and the homopolymers, using the Taguchi method of experimental design, determine that the most significant factor is the temperature, followed by PEN content and then the initial stress, and interaction effects between factors are insignificant. To fit the relaxation curves of the PBT/PEN blends and the homopolymers at different temperatures, PEN contents and initial stresses, four different equations have been used. The coefficients of the equation that fit best are used to predict the relaxation behaviour of PBT/PEN blends at a temperature between 30C and 60C, and at the initial stresses of 7 MPa.

This investigation presents research on the characteristic properties of Nylon66 and poly(ethylene naphthalate) (Ny66/PEN), and poly(butylene terephthalate) and poly(ethylene naphthalate) (PBT/PEN) blends with several weight compositions made by melt blending, by the use of 13C and 1H Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and Dynamic mechanical thermal analysis (DMTA), X-ray diffraction (X-RD), tensile, impact and stress relaxation tests. Ny66/PEN blends including several additives do not improve the miscibility of the constituent polymers and show lower tensile strength than those of homopolymers. However, PBT/PEN blends reveal improved tensile strengths of the blends between the ROM and MROM predictions lines with more than 50 % volume fraction of PEN. On the other hand, NMR spectra show no evidence of interchange reaction in both Ny66/PEN and PBT/PEN blends. SEM micrographs of fracture surfaces in PBT/PEN blends reveal a very small (sub-micron) domain size in contrast to large domains in Ny66/PEN blends, which indicates partial miscibility of PBT and PEN. DSC and DMTA demonstrate partial miscibility of PBT/PEN blends by the change of Tgs of each component according to the weight proportions of the constituent polymers. Stress relaxation tests for the specimens of PBT/PEN blends and the homopolymers, using the Taguchi method of experimental design, determine that the most significant factor is the temperature, followed by PEN content and then the initial stress, and interaction effects between factors are insignificant. To fit the relaxation curves of the PBT/PEN blends and the homopolymers at different temperatures, PEN contents and initial stresses, four different equations have been used. The coefficients of the equation that fit best are used to predict the relaxation behaviour of PBT/PEN blends at a temperature between 30C and 60C, and at the initial stresses of 7 MPa.

This investigation presents research on the characteristic properties of Nylon66 and poly(ethylene naphthalate) (Ny66/PEN), and poly(butylene terephthalate) and poly(ethylene naphthalate) (PBT/PEN) blends with several weight compositions made by melt blending, by the use of 13C and 1H Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and Dynamic mechanical thermal analysis (DMTA), X-ray diffraction (X-RD), tensile, impact and stress relaxation tests. Ny66/PEN blends including several additives do not improve the miscibility of the constituent polymers and show lower tensile strength than those of homopolymers. However, PBT/PEN blends reveal improved tensile strengths of the blends between the ROM and MROM predictions lines with more than 50 % volume fraction of PEN. On the other hand, NMR spectra show no evidence of interchange reaction in both Ny66/PEN and PBT/PEN blends. SEM micrographs of fracture surfaces in PBT/PEN blends reveal a very small (sub-micron) domain size in contrast to large domains in Ny66/PEN blends, which indicates partial miscibility of PBT and PEN. DSC and DMTA demonstrate partial miscibility of PBT/PEN blends by the change of Tgs of each component according to the weight proportions of the constituent polymers. Stress relaxation tests for the specimens of PBT/PEN blends and the homopolymers, using the Taguchi method of experimental design, determine that the most significant factor is the temperature, followed by PEN content and then the initial stress, and interaction effects between factors are insignificant. To fit the relaxation curves of the PBT/PEN blends and the homopolymers at different temperatures, PEN contents and initial stresses, four different equations have been used. The coefficients of the equation that fit best are used to predict the relaxation behaviour of PBT/PEN blends at a temperature between 30C and 60C, and at the initial stresses of 7 MPa.

Orientador: José Carlos Marconato / Banca: Regina Teresa Rosim Monteiro / Banca: Adriana de Campos Pastre / Resumo: Recentemente o mundo começou a se preocupar com o consumo exacerbado de embalagens e a sua rápida descartabilidade. Por conseguinte, alternativas de amenização deste problema têm sido propostas tais como a utilização de plásticos biodegradáveis, o uso de blendas poliméricas e o emprego de aditivos que facilitem a biodegradação. Sendo assim, este trabalho teve por objetivo avaliar os diferentes tratamentos: foto, bio e foto/biotratamento, aplicados na degradação de filmes finos de PEBD, PHB e de suas blendas, empregando o fungo P. chrysosporium CCB 478 no processo biodegradativo. As blendas de PEBD/PHB foram preparadas nas composições de 90:10, 80:20 e 70:30 (m/m) juntamente com os filmes de homopolímeros pelo processo de prensagem sob aquecimento. As amostras foram submetidas à radiação UV e em seguida foram aplicados os testes de biodegradação em meio mineral líquido com o fungo P. chrysosporium CCB 478 pelo período de 120 dias. Análises de perda de massa, ângulo de contato, FTIR, análises visuais, microscopia óptica, MEV, foram técnicas utilizadas para avaliar a biodegradação. O fototratamento realizado com todas as amostras dos filmes foi relevante para o processo de adesão e colonização da superfície dos filmes. As blendas de composição 70/30 e 80/20 apresentaram alterações morfológicas e estruturais mais significativas, por MEV e FTIR, além de apresentaram melhores resultados de biodegradação, após a fotoirradiação. / Abstract: Recently the world began to worry about the high consumption and rapid disposability of packaging. Therefore, alternatives to improve this problem have been proposed such as use of biodegradable plastics, polymer blends and additivies which facilitates the biodegradation. Thus, this study aimed to evaluate the results of different treatments: biotreatment, phototreatment, and photo/biotreatment, applied on the degradation of thin films of LDPE, PHB and its blends, using as fungus Phanerochaete chrysosporium CCB 478 in biodegradation process. Blends of LDPE/PHB were prepared in the compositions of 90:10, 80:20 and 70:30 (m/m) along with homopolymers films by pressing process under heating. Samples were exposed to UV radiation and then were submitted to the biodegradation tests in liquid mineral medium with the P. chrysosporium CCB 478 fungus for 120 days. Analysis of weight loss, contact angle, FTIR, visual analysis, optical microscopy and SEM, were employed to estimate biodegradation. Phototreatment applied to all films was relevant to the adhesion process and colonization the surface films. The blends of composition 70/30 and 80/20 showed significant morphological and structural changes, verified by SEM and FTIR techniques, besides showed better results of biodegradation after photoirradiation. / Mestre

abstract: The trend towards using recycled materials on new construction projects is growing as the cost for construction materials are ever increasing and the awareness of the responsibility we have to be good stewards of our environment is heightened. While recycled asphalt is sometimes used in pavements, its use as structural fill has been hindered by concern that it is susceptible to large long-term deformations (creep), preventing its use for a great many geotechnical applications. While asphalt/soil blends are often proposed as an alternative to 100% recycled asphalt fill, little data is available characterizing the geotechnical properties of recycled asphalt soil blends. In this dissertation, the geotechnical properties for five different recycled asphalt soil blends are characterized. Data includes the particle size distribution, plasticity index, creep, and shear strength for each blend. Blends with 0%, 25%, 50%, 75% and 100% recycled asphalt were tested. As the recycled asphalt material used for testing had particles sizes up to 1.5 inches, a large 18 inch diameter direct shear apparatus was used to determine the shear strength and creep characteristics of the material. The results of the testing program confirm that the creep potential of recycled asphalt is a geotechnical concern when the material is subjected to loads greater than 1500 pounds per square foot (psf). In addition, the test results demonstrate that the amount of soil blended with the recycled asphalt can greatly influence the creep and shear strength behavior of the composite material. Furthermore, there appears to be an optimal blend ratio where the composite material had better properties than either the recycled asphalt or virgin soil alone with respect to shear strength. / Dissertation/Thesis / M.S. Civil Engineering 2011

O calçado está presente desde os primórdios da história da humanidade e sua evolução incorporou novos materiais que o tornaram mais resistente e seguro. Além de proteger os pés, o calçado possui um apelo de moda e estilo que leva à criação de modelos que utilizam saltos altos e finos, ultrapassando os 100 mm de altura. Tais sapatos exigem componentes estruturais resistentes que tragam segurança ao andar sendo o mais importante deles a palmilha de montagem, ao redor da qual o calçado é construído. Produzida em celulose ou polímeros tais como ABS (Acrilonitrila Butadieno Estireno) e PP (Polipropileno), a palmilha de montagem utilizada em calçados de salto alto leva em seu interior uma alma-de-aço fabricada em aço temperado que confere a resistência e rigidez necessária para resistir aos esforços a que a palmilha é submetida no caminhar. Com objetivo de obter um material resistente que permita a fabricação de palmilhas de montagem sem a necessidade de utilização de almas-de-aço, foram avaliadas duas famílias de blendas, uma constituída de PA-6 (Poliamida 6) com ABS e outra de PA-6 com Copoliéster, e seus respectivos compósitos contendo fibra de vidro em sua composição. Estes materiais foram extrusados e injetados em corpos de prova e suas propriedades físicas, mecânicas, térmicas e morfológicas avaliadas. Também foram obtidas palmilhas de montagem que foram submetidas a ensaios de fadiga. Os resultados indicaram que as blendas não possuem a rigidez estrutural necessária para aplicação em palmilhas de montagem, enquanto que os compósitos contendo fibra de vidro alcançaram desempenho satisfatório que lhes conferem potencial de utilização em palmilhas de montagem de calçados de salto alto sem a utilização de alma-de-aço. / Footwear has been present since the early days of human history and its evolution has incorporated new materials that have made it stronger and safer. In addition to protecting the feet, the footwear has a model of fashion and style that leads to the creation of models that use thin and high heels, exceeding 100 mm in height. Such shoes require tough structural components that bring safety when walking and the most important is the lasting insole. Around of it the footwear is built. Produced in cellulose or polymers such as ABS (Acrylonitrile Butadiene Styrene) or PP (Polypropylene), a lasting insole used in high-heels shoes carries inside a shank made of tempered steel that provides strength and stiffness required and submitted during walking. With the aim of obtaining a resistant material to allow the manufacture to build an insole without the need to use a steel shank, once we evaluated two blend families, a PA-6 (Polyamide 6) with ABS and PA-6 with Copolyéster, and their respective composites containing fiberglass in their composition. These materials were extruded and injected into test bodies and their physical, mechanical, thermal and morphological properties were evaluated. Also were submitted to assembly insoles that were submitted to fatigue tests. The results indicate that as blends do not have a structural rigidity required for the application in lasting insoles, while composites with fiberglass have achieved satisfactory performance which gives them potential for use as lasting insole used in high-heels shoes without shank steel.

A primeira etapa deste estudo foi o processamento de amido de milho com diferentes proporções de glicerol, água e epicloridrina (EPI) utilizando reômetro de torque. Após a avaliação visual das amostras obtidas, definiu-se pela proporção com 30 g de amido, 24g de glicerol, 6g de água e 0,6g de EPI para ser produzida em extrusora reativa. O material resultante foi denominado como TPSR sendo posteriormente utilizado como carga para ser dispersa em matriz poli (acido lático) (PLA) para a obtenção de blendas de PLA/TPSR. As blendas de PLA/TPSR foram preparadas por extrusão com proporções de 5%,10% e 30% de TPSR em relação à quantidade de massa da matriz PLA e que neste estudo são denominadas respectivamente como PLA/TPSR5, PLA/TPSR10 e PLA/TPSR30. A morfologia, propriedades térmicas e propriedades mecânicas das blendas obtidas foram avaliadas por microscopia eletrônica de varredura (MEV), calorimetria exploratória diferencial (DSC), análise termogravimétrica (TGA), análise termo-dinâmico mecânica (DMA) e ensaio de impacto IZOD. As blendas apresentaram em sua morfologia poros, cavidades e grânulos de amido residual aumentando sua presença em função da quantidade de TPSR, o que indica um baixo nível de interação entre PLA e TPSR e que pode ser relacionado à diminuição da resistência ao impacto. Resultados de calorimetria exploratória diferencial (DSC) permitiram verificar que a Tg e Tm das misturas diminuiu com o acréscimo da carga TPSR na matriz PLA. A mesma tendência foi observada nas curvas de TGA que revelaram que as blendas de PLA/TPSR decompõem-se mais facilmente e a menores faixas de temperatura. O módulo de armazenamento aumentou para blendas com 5% e 10% de TPSR e diminuiu drasticamente para PLA/TPSR30. / The first step of this study was corn starch processing with different proportions of glycerol, water and epichlorohydrin (EPI) using a torque rheometer. After the visual evaluation of the samples, the proportion defined was 30 g of starch, 24 g of glycerol, 6 g of water and 0.6 g of EPI to be produced in reactive extruder. The resulting material was designated as TPSR subsequently used as filler to be dispersed in matrix poly (lactic acid) (PLA) to obtain PLA / TPSR blends. The blends of PLA / TPSR were prepared by extrusion with proportions of 5%, 10% and 30% of TPSR with relation to the amount of mass of the PLA array and that in this study are respectively referred as PLA / TPSR5, PLA / TPSR10 and PLA / TPSR30. The morphology, thermal properties and mechanical properties of the resulting blends were evaluated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), thermo-dynamic mechanical analysis (DMA) and IZOD impact test. The blends had pores, cavities and residual starch granule in its morphology, increasing its presence due to the amount of TPSR, which indicates a low level of interaction between PLA and TPSR and that can be related to a decrease in impact resistance. Differential scanning calorimetry results (DSC) helped confirm that the Tg and Tm of the mixtures decreased with TPSR load increase in PLA matrix. The same trend was observed in the TGA curves that showed that the blends of PLA / TPSR decompose more easily and at lower temperature ranges. The storage modulus increased in blends with 5% and 10% and dramatically decreased to TPSR PLA / TPSR30.