Determinação turbidimétrica de dipirona em fluxo utilizando um reator contendo cloreto de prata imobilizado em resina poliéster

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

RADIOGRAFIA E MACROSCOPIA do JOELHO APÓS ESTABILIZAÇÃO EXTRA-ARTICULAR UTILIZANDO FÁSCIA LATA, FIO DE POLIÉSTER TRANÇADO OU FIO DE POLIAMIDA PARA CORREÇÃO da RUPTURA do LIGAMENTO CRUZADO CRANIAL em CÃES

A ruptura do ligamento cruzado cranial é uma das principais doenças ortopédicas que afetam os cães. Muitas técnicas cirúrgicas foram descritas no intuito de aliviar a dor, restaurar a estabilidade biomecânica do joelho e prevenir a progressão da osteoartrite. Fáscia lata, fio de poliéster trançado e fio de poliamida foram empregados na estabilização do joelho após excisão do ligamento cruzado cranial em cães, os quais foram submetidos à avaliação radiográfica e macroscópica da articulação. Neste estudo, foram utilizados 18 cães com massa corporal superior a 15Kg (peso médio - 19,67kg), separados em 3 grupos eqüitativos correspondentes a cada técnica, avaliados durante 30 e 60 dias. Ao exame radiográfico, independentemente de grupo, os cães apresentaram evidência de efusão articular moderada a severa, distensão da cápsula articular e, na maioria dos casos, ausência de sinais de doença articular degenerativa. Ao exame macroscópico da articulação do joelho observou-se espessamento da cápsula articular e tecidos moles periarticulares, erosão da cartilagem articular dos côndilos femorais em todos os grupos e afrouxamento dos fios nos cães submetidos às técnicas de estabilização extra-articular com fio de poliéster trançado e fio de poliamida.

Modificação superficial de fibras de juta com descarga corona para melhora da aderência com matriz poliéster

Seeking alternatives for the total or partial substitution of synthetic fibers for natural fibers, with reinforcement in polymeric materials, this work was conducted with the objective of evaluating the treatment with corona discharge on the adherence of juta fibers with resin. The fibers were exposed to corona discharge for 1, 5, 10 and 15 minutes, as well as after treatment with hot water, molding composites fiber-reinforced with filaments treated for 10 and 15 minutes, and without the treatment. The chemical structures were evaluated by spectrometry in the region of Fourier transform infrared with attenuated total reflection (FTIR/ATR), observing the formation of a new band and the increase in the absorption of groupings with oxygen. The thermal analyses, such as thermogravimetry (TG) and differential scanning calorimetry (DSC) revealed the degradation of cellulose, hemicellulose and lignin. The microstructural characterization by scanning electron microscopy (SEM) showed changes in the surface of the fiber, such as roughness, superficial depressions, surface degradation and cavity formation. The adhesion of the fibers was evaluated by the pullout test, allowing us to verify the increase in adhesion strength after treatment with corona discharge. In conclusion, the treatment with corona discharge changes the surface of the juta fibers, resulting in better adherence with the resin.

Comportamento mecânico de material compósito de matriz poliéster reforçado por sistema híbrido fibras naturais e resíduos da indústria madeireira

Neste trabalho, materiais compósitos de matriz poliéster reforçados por fibras curtas de sisal, por resíduo de madeira e por sistema híbrido sisal/resíduo de madeira, dispostos aleatoriamente foram produzidos, utilizando-se o menor nível possível de processamento tecnológico nas etapas produtivas, com vistas a se produzir um compósito tecnicamente viável a pequenos produtores. A matriz de poliéster utilizada foi a tereftálica pré-acelerada com naftenato de cobalto e curada a temperatura ambiente com peróxido de metil-etil-cetona (MEK) em diferentes proporções em relação à resina, 0,33%, 1,66%, 3,33% e 5,00% em volume, de forma a se avaliar a influência deste nas propriedades mecânicas. As fibras de sisal foram cortadas manualmente nos comprimentos de 5, 10 e 15mm e utilizadas da maneira como adquiridas, sem tratamento superficial. O resíduo de madeira utilizado foi o pó de lixadeira da madeira maçaranduba. Os compósitos foram fabricados por moldagem manual, sem pressão e a temperatura ambiente. Foram fabricados corpos de prova de matriz pura, compósitos reforçados por sisal, variando-se o comprimento das fibras, compósitos reforçados por pó de maçaranduba e compósitos de reforço híbrido, sisal/pó de madeira, em diferentes proporções entre os constituintes. As propriedades mecânicas foram avaliadas por ensaios de tração e impacto charpy e as superfícies de fratura geradas foram avaliadas por microscopia eletrônica de varredura de modo a se correlacionar os aspectos de fratura com as propriedades mecânicas. Foi determinada a massa específica de cada série de corpos de prova fabricada, bem como a fração volumétrica dos reforços nos compósitos. Os resultados demonstraram que com o aumento do comprimento da fibra de sisal a resistência à tração e ao impacto dos compósitos foi incrementada, alcançando, o compósito com fibras de sisal de 15 mm, o melhor desempenho mecânico dentre as séries testadas. Por outro lado, a heterogeneidade granulométrica do pó de maçaranduba teve efeito negativo sobre as propriedades mecânicas dos compósitos. Os compósitos híbridos sisal/pó de madeira com maior teor de fibras, alcançaram 80% do desempenho obtido para os compósitos de fibras de sisal.

Fabricação e caracterização de material compósito de resina poliéster reforçada por tecido de fibra de tururi extraído da palmeira de ubuçu (Manicaria saccifera)

Neste trabalho é apresentada a fabricação e caracterização de um material compósito de matriz polimérica reforçada por fibras naturais. A matriz é um poliéster teraftélica insaturada préacelerada obtida comercialmente como Denverpoly 754 e o agente de cura utilizado foi o peróxido de Mek (Butanox M- 50), na proporção de 0,33 % , em volume. A fibra natural usada foi o tururi, obtida da região do Marajó, município de Muaná. O tecido de fibra de tururi foi submetido a dois tipos de abertura no sentido transversal, de [50 e 100]%, em relação a uma largura original. A fabricação do material compósito foi através do método da laminação manual (hand lay up), seguido de uma pressão controlada através de pesos previamente quantificados. Características físicas, mecânicas e microscópicas foram obtidas para a fibra e o material compósito, obtendo-se resistência a tração, massa específica, gramatura do tecido, fração mássica e imagens microscópicas antes e depois do ensaio de tração para o tecido da fibra e ensaio de tração depois do ensaio de tração para o material compósito. O tecido de tururi apresentou resistência a tração de 29,95 MPa (sem abertura), 12,27 MPa (abertura de 50 %) e 9,38 MPa (abertura de 100 %). A abertura provoca a diminuição da resistência à tração do tecido de tururi. A gramatura do tecido diminuiu com a abertura do tecido. A fração mássica do tecido do compósito foi de 14,39 % (sem abertura), 9,35 % (abertura de 50 %) e 7,19 % (abertura de 100 %). A resistência a tração do compósito foi de 35,76 MPa (sem abertura), 19,01 MPa (50 % de abertura) e 16,8 MPa (100 % de abertura). A resistência mecânica apresentou valores aproximados aos encontrados na literatura para materiais compósitos reforçados por fibras naturais. As imagens obtidas em microscopia eletrônica de varredura corroboraram com as propriedades mecânicas obtidas para cada situação do material e fibras.

Influência da Espessura nas Propriedades Mecânicas de Compósitos Híbridos Interlaminares de Curauá/Vidro/Poliéster

The interest in the use of vegetable fibers (e.g. jute, sisal and curaua) for more noble applications, such as reinforcement in polymeric composite materials, has increased over the years due to a variety of aspects, especially those related to environmental legislation and community awareness regarding the life cycle of products. In this context, the aim of this work is to develop hybrid interlaminate curaua/glass/insaturated polyester composites by hot compression molding and to analyze their mechanical properties as a function of the thickness of the laminate. The short beam strength of the thickest sample decreased due to its higher void content. Furthermore, the thinnest sample showed lower hardness, and lower impact, tensile and Iosipescu shear strength, partly attributed to its lower fiber volumetric fraction. Thus, in general, the most adequate laminate was the one comprising eight layers, four of which were of glass fiber and four of curaua fiber, but only if flexural loading is not critical.

Análisis del comportamiento de las tuberías de poliéster reforzado con fibra de vidrio con capa de arena

Aunque las primeras fábricas de tubos de poliéster reforzado con fibra de vidrio en España datan del año 1984, no es sino hasta el año 1996 cuando se comienza su utilización masiva como un sustituto de las tuberías de fribrocemento, que ya habían sido prohibidas por la legislación, debido a los efectos cancerígenos de este material. Desde entonces se ha prodigado la utilización de todas las diferentes tipologías de esta clase de tubería, de conformidad a los procesos de fabricación empleados que se encuentran recopilados en el AWWA Manual M45 (Fiberglass Pipe Design), obteniéndose muy diversos resultados. Durante estos años, ha surgido una creciente preocupación en los usuarios de este tipo de tuberías dadas las continuas y numerosas averías en todo el ámbito geográfico. Esto ha promovido el desarrollo de la presente investigaicón, que se ha dividido en dos partes y que ha concluido con la determinación de un nuevo mecanismo específico de fractura. La primera parte se centró en la obtención y desarrollo del modelo teórico que hemos venido a denominar como "Teoría de la Caja Mecánicamente Contaminada", y que está basado en la contaminación o separación por un impacto de dos de las tres capas que forman la tubería, la capa intermedia de arena y la capa más interna o "inner layer". La consecuencia es la disminución del canto resistente, la rotura del inner layer y la entrada de fluido a la capa de arena. Para la evaluación de la magnitud de esta separación se ha desarrollado un modelo analítico que ha determinado la existencia de una relación cuadrática que la rige, y que ha sido verificado mediante ensayos de impacto sobre probetas de tuberías, alcanzando ajustes de hasta el 92%. Así, se ha determinado que impactos de muy baja intensidad, del entorno de 90 a 160 Julios en tuberías Filament Winding continuo PN 16-20 (de 800 a 1000mm) pueden comprometer seriamente la integridad estructural de la tubería sin dejar, en un principio, muesca o traza alguna que pueda alertar del problema. Los siguientes pasos en el estudio se dirigieron a determinar qué otros mecanismos, aparte del golpe, podrían contaminar la tubería y a estudiar el consiguiente avance de la fractura a las capas externas. Se trataba además de analizar la aparición en el tubo de unas misteriosas manchas en forma de "piel de leopardo" y de otros fenómenos aparecidos en las averías como que algunas de las deformaciones de la rotura por presión interna son hacia el interior del tubo y no al revés, como habría sido de esperar a priori. Se optó entonces por comenzar la que ha constituido la segunda parte de la investigación. Para ello se recurrió a realizar ensayos hidráulicos en banco de pruebas a alta presión, cuyos resultados fueron sorprendentes al descubrir que en el proceso se producía la hidrólisis de la resina de poliéster no catalizada que fluía hacia el exterior del tubo. Como consecuencia se llevaron a cabo nuevos ensayos físicos y químicos para estudiar la migración del material y la hidrólisis producida en el proceso de fractura. En este estudio, resultó muy relevante el hecho de sobrepasar o no la presión que producía el desagarro entre las capas del tubo. En definitiva, en esta investigación, que ha constado de estudios analíticos y estudios experimentales, químicos y numéricos, se ha determinado un nuevo mecanismo de fractura que explica gran parte de los fallos acontecidos en las tuberías de poliéster reforzado con fibra de vidrio. Como aplicación se exponen recomendaciones para mejorar el comportamiento mecánico de esta tipología y evitar así los sobrecostes millonarios producidos por su reposición. Numerous and continuous failures in fiberglass reinforced polyester pipes of different companies and manufacturing processes of the AWWA Manual M45 (Fiberglass Pipe Design), have prompted the development of this research, that has concluded with a specific mechanism describing pipe fractures. This research was carried out via two independent studies. The first one is the development of the hypothesis that turned into the Mechanically Contaminated Layer Theory. This theory describes the fracture mchanism which explains a significant part of massive failures due to the existence of a sand layer placed near the neutral axis in the core making the composite very sensitive to impacts in fibreglass reinforced polyester pipes. These failures create interface delamination and consequently fluid can leak into supporting sand backfill thereby iniating the fracture process. In order to assess the delimination magnitude, an analytic method is developed and a squared root law between delamination and energy applied proposed. Vertical blunt ram testts on samples extracted from complete pipes have been carried out to verify this theory, reaching a goodness of fit up to 92%. It is concluded that low energy impacts, around 90-160J in 800-1000mm diameter PN 16-20 continuous filament winding pipes, can seriously compromise their structural integraty with no external trace. The next step in the study was to determine what other mechanism, apart from the brittle hit, could contaminate the pipe and to analyse the consequente advance of the fracture to the external layers. Another aim was to analyse two phenomena occurred in real pipe failures. The first one is the appearance on the tube of "leopard fur" stains on some of the analysed failures, and the other phenomenon is the "inverse fracture", in which the deformations of the failure due to internal pressure are towards the inside of the tube and not the other way round, as it would be expected. It was then chosen to follow a new branch of the investigation by hydraulic high-pressure bench tests that study seepage and load transmission. The results were very surprising as it was discovered that in the process, hydrolysis of the non-catalysed polyester resin occured, flowing towards the outer of the pipe, which entailed the development of chemical and physical tests of the exuded material to study material migration and hydrolysis of the fracture process. In this particular study it was relevant to exceed or not the pressure that produced the rip between the layers of the tube. In conclusion, a new breakage mechanism in FRP pies with sand-filled layer has been found, which explains a high part of the failure global cases. The whole failure process is justified by the Mechanically Contaminated Layer Theory, which has been corroborated by means of analytical, numerical and experimental studies. Several recommendations are also provided in order to improve the mechanical behaviour of this typology and avoid the millionaire overruns generated by its massive failures.

Análisis de la degradación, desintegración y biodegradabilidad de bolsas de poliéster y almidón en compostaje de residuos urbanos: escalas de laboratorio e industrial

El principal objetivo de esta tesis es verificar que las bolsas biodegradables de copoliéster (PBAT) con base de almidón (UNE 13432: 2001) alcanzan los niveles de degradación y desintegración requeridos para su certificación (%D= ≥ 90%), medido en condiciones reales de compostaje industrial. Para lograr mayor representatividad, los ensayos se han realizado en dos plantas de tratamiento de residuos urbanos en las que se aplican las técnicas de compostaje más comunes en el ámbito europeo y nacional, pila y túnel, mediante el compostaje de la FORSU. Se llevaron a cabo dos tipos de ensayos. Por un lado se realizó un ensayo escala de laboratorio (ISO 14855), orientado como indicador de la biodegradabilidad del polímero en el formato bolsa comercializado. Por otro lado, se desarrollaron una batería de ensayos realizados en dos plantas de compostaje de residuos urbanos: el Centro de Tratamiento de Residuos de Torija (Ávila), que realiza el compostaje mediante pila volteada, y el Centro de Tratamiento de Residuos de Arenas de San Pedro (Ávila), que realiza el compostaje en túnel. Para la obtención de resultados se han contrastado parámetros como el porcentaje de biodegradación (%B), el porcentaje de desintegración (%D), degradación superficial de las muestras, calidad de la FORSU inicial (caracterizaciones y análisis físico-químico) y calidad del MB final (análisis físico-químico e IG). Atendiendo al objetivo general se demuestra que las bolsas de copoliéster con base de almidón certificadas (UNE EN 13432:2001) han alcanzado el 94,37% ± 0,007% de desintegración en la planta de compostaje de FORSU con pila volteada; y el 86,36% ± 0,151% en la planta de compostaje de FORSU con túnel estático. A pesar de la aparente diferencia, el resultado del análisis concluye que no existen diferencias estadísticamente significativas entre técnicas de compostaje. La presencia de impropios y el contendido de metales pesados en la FORSU no han influido en la desintegración de las bolsas de estudio. En cambio, se ha detectado una influencia estadísticamente significativa entre el contenido de materia orgánica total y de nutrientes de la FORSU y el porcentaje de desintegración de las muestras. No se detectado una relación estadísticamente significativa entre la presencia de bolsas de estudio en las concentraciones definidas, y la calidad del MB, medido mediante el análisis físico-químico, microbiológico y el IG del MB. La concentración de los metales pesados en la mayoría de las muestras de material bioestabilizado cumplió con los límites establecidos para la categoría A, aplicable al “compost” procedente de la fracción orgánica recogida de forma separada según el RD 506/2013 de productos fertilizantes. También se detectó fitotoxicidad alta (FA) según la metodología y criterios de valoración definidos. Esta fitotoxicidad no está relacionada con la presencia de las bolsas de estudio sino con la calidad de la FORSU de partida y/o con los productos liberados durante el proceso de compostaje. ABSTRACT The main objective of this thesis is to verify that the copolyester (PBAT) starch based (UNE 13432: 2001) biodegradable bags reach levels of degradation and disintegration required for it´s certification (% D = ≥ 90%), measured in terms of real industrial composting. The tests were performed at two municipal solid waste (MSW) treatment plants, where the most common composting techniques applied at European and national level were represented, windrow and tunnel. Two types of tests were carried out: First, a laboratory scale test (ISO 14855), as an indicator of the polymer biodegradation of the commercialized bag format. Second, a battery of tests was conducted at two MSW composting plants, Waste Treatment Center of Torija (Guadalajara), that makes compost by turned pile, and the Waste Treatment Center of Arenas de San Pedro (Ávila), where makes compost by static tunnel. To obtain the results, the parameters such as the biodegradation percentage (% B), the disintegration percentage (% D), surface degradation of the samples, the initial quality of FORSU (characterizations and physico-chemical analysis) and bioestabilithated material (MB) quality (physico-chemical analysis and IG) have been compared. In reference to the general aim It shows that the copolyester starch based certified (UNE-EN 13432) bags have reached 94.37% ± 0.007% of disintegration in the composting turned pile; and 86.36% ± 0.151% in the static tunnel. Despite the apparent difference, the result of the analysis concludes that there are no statistically significant differences between composting techniques. The presence of non-compostable materials and the heavy metals content in the FORSU has not affected in the disintegration of the bags. Instead, It has been detected a statistically significant influence over the total organic matter content and nutrient content in the FORSU and the samples disintegration percentage. A statistically significant relationship between the bag presence in the defined concentrations and the quality of MB measured by physical-chemical analysis, microbiological analysis and IG of the MB is not detected. The concentration of heavy metals in most MB samples was within the limits of A-Class, applicable to "compost" from organic waste collected separately according to RD 506/2013 of fertilizers. High phytotoxicity (FA) was also detected according to the methodology and evaluation defined. The phytotoxicity is not related to the presence of bags but it is with the FORSU initial quality and/or with the products released during the composting process.

Obtenção e caracterização de um compósito polimérico de matriz poliéster e reforço/carga de tecido plano de algodão

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

Obtenção e caracterização de um compósito polimérico de matriz poliéster e reforço/carga de tecido plano de algodão

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

Obtenção, caracterização e utilização de um compósito com matriz de resina poliéster e carga de fibras de sisal

The constant search for sustainable alternatives has earned great effort of researchers in research and obtaining new materials, encouraging the rise of eco-friendly productive development and providing simple and practical solutions to economic profitability. In this sense, the use of materials derived from natural renewable sources, vegetables, has great potential applicability to sustainable development. As alternative materials plant fibers can be applied to production of a range of composite materials easing the use of materials derived from non-renewable this thesis were sisal mats used for achieving a composite matrix having as one orthophthalic polyester resin. The webs were subjected to surface treatment in boiling water for 15 minutes. The webs of sisal fibers used were, respectively, 5%, 10% and 15% of the composite weight. The composite was obtained and characterized mechanically and thermally to the chosen formulations. several plates of the composite to obtain the body of evidence for the characterization tests complying with the relevant rules were made. The obtained composites showed strength tensile and bending lower than the array, so it can be used where are required low load requests. The most significant result of the composite studied given to the impact energy absorption, far superior to the matrix used. Other properties were highlighted in oil absorption, and density. It proved the feasibility of obtaining the composite for the three formulations studied C5, C10 and C15 being the most feasible to C10. To demonstrate the feasibility of using composite were made a wall clock, a bench, a chair and a shelf, low mechanical stress structures. It was concluded that the sisal rugs exercised the load function in the composite.

Obtenção, caracterização e utilização de um compósito com matriz de resina poliéster e carga de fibras de sisal

The constant search for sustainable alternatives has earned great effort of researchers in research and obtaining new materials, encouraging the rise of eco-friendly productive development and providing simple and practical solutions to economic profitability. In this sense, the use of materials derived from natural renewable sources, vegetables, has great potential applicability to sustainable development. As alternative materials plant fibers can be applied to production of a range of composite materials easing the use of materials derived from non-renewable this thesis were sisal mats used for achieving a composite matrix having as one orthophthalic polyester resin. The webs were subjected to surface treatment in boiling water for 15 minutes. The webs of sisal fibers used were, respectively, 5%, 10% and 15% of the composite weight. The composite was obtained and characterized mechanically and thermally to the chosen formulations. several plates of the composite to obtain the body of evidence for the characterization tests complying with the relevant rules were made. The obtained composites showed strength tensile and bending lower than the array, so it can be used where are required low load requests. The most significant result of the composite studied given to the impact energy absorption, far superior to the matrix used. Other properties were highlighted in oil absorption, and density. It proved the feasibility of obtaining the composite for the three formulations studied C5, C10 and C15 being the most feasible to C10. To demonstrate the feasibility of using composite were made a wall clock, a bench, a chair and a shelf, low mechanical stress structures. It was concluded that the sisal rugs exercised the load function in the composite.