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Made available in DSpace on 2014-12-17T14:58:14Z (GMT). No. of bitstreams: 1 JoseOO_DISSERT.pdf: 1240113 bytes, checksum: dbf41a478040a880c57e2dbf04e10cda (MD5) Previous issue date: 2012-03-30 / The objective of this research is the fabrication of a composite reinforced with dyed sisal fiber and polyester matrix for application in the fields such as, fashion, clothing, interior textiles; fashion accessories are some of the examples. For the fabrication of the composite, the sisal fibers were subjected to processes such as: chemical treatment with sodium hydroxide (NaOH) in the removal of impurities; bleaching for removing the yellowish color of the natural fiber and dyeing with direct dyes to confer the colors blue, green and orange. The search for new technologies ecologically correct has become a major concern in recent decades. Studies show that composite polymer reinforced by natural fibers is suitable for a large number of applications, and its use is advantageous in terms of economic and ecological. The dyed fibers were cut to a length of 30 mm, is used in the confection of webs. For this purpose, a web preparer by immersion, developed in the Laboratory of Chemical Textile of UFRN. The composite sheets measuring 300 x 300 x3 mm were molded by compression, with unsaturated orthophthalic polyester as matrix, and the samples in sizes 150 x 25 x 3 mm were cut with the aid of a laser machine, to be subjected to traction and flexion. The mechanical properties of traction and flexion in three points were performed in the Laboratory of metal and mechanical tests of Materials Engineering of UFRN. The resulting samples from the tests were evaluated in scanning electron microscope (SEM) at CTGas RN. On the basis of the analysis of the results from the mechanical tests, it was observed that the composite had good mechanical behavior, both in traction as in flexion. Furthermore, it was observed that in the water absorption test, the samples had a different percentage among themselves, this occurred due to the variation of density found in the fibre webs. The images of the SEM showed the failures from the manufacturing process and the adhesion of fibre/matrix. When the samples were prepared with the dyed fibers to be applied in fashion, the results were positive, and it can be concluded that the main objective of this work was achieved / A busca por novas tecnologias ecologicamente corretas tem se tornado uma grande preocupa??o nas ?ltimas d?cadas. Estudos comprovam que comp?sitos polim?ricos refor?ados por fibras naturais s?o adequadas a um grande n?mero de aplica??es e seu uso ? vantajoso em termos econ?micos e ecol?gicos. O objetivo desta pesquisa ? a fabrica??o de um comp?sito refor?ado com fibra de sisal tingida e matriz de poli?ster para aplica??o na moda: vestu?rio, t?xteis lar, acess?rios de moda etc. Para o seu beneficiamento, as fibras de sisal foram submetidas aos diversos processos: tratamento qu?mico com hidr?xido de s?dio (NaOH) na retirada das impurezas; alvejamento para remo??o da cor amarelada natural da fibra e tingimento com corantes diretos para conferir as cores azul, verde e alaranjado. As fibras tingidas foram cortadas com comprimento de 30 mm e utilizadas na confec??o das mantas. Para isso utilizou-se um preparador de manta por imers?o, desenvolvido no Laborat?rio de Qu?mico T?xtil da UFRN. Os comp?sitos medindo 300 x 300 x 3 mm foram moldados por compress?o, com poli?ster insaturado ortoft?lico como matriz, e as amostras nos tamanhos 150 x25 x3 mm foram cortadas com aux?lio de uma m?quina ? laser, para serem submetidas ? an?lise mec?nica de tra??o e flex?o. As propriedades mec?nicas de tra??o e flex?o em tr?s pontos foram realizadas no Laborat?rio de Metais e Ensaios Mec?nicos de Engenharia de Materiais da UFRN. As amostras resultantes das propriedades mec?nicas foram avaliadas no Microscopio Eletronico de Varredura (MEV) no CTG?s RN. Com base nas an?lises dos resultados dos ensaios mec?nicos, observou-se que os compositos tiveram bom comportamento mec?nico, tanto na tra??o como na flex?o. Tamb?m observou-se que no ensaio de absor??o de ?gua, as amostras tiveram um percentual diferente entre si, isso ocorreu devido ? varia??o da densidade encontrada nas mantas. As imagens do MEV mostraram as falhas provenientes do processo de fabrica??o e a ades?o fibra/matriz. Quando foram preparadas as amostras com as fibras tingidas para serem aplicadas na moda, os resultados foram positivos e pode-se concluir que o objetivo principal do presente trabalho foi atingido

Made available in DSpace on 2014-12-17T14:58:21Z (GMT). No. of bitstreams: 1 ElisangelaBNH_DISSERT.pdf: 5500408 bytes, checksum: 312e914c2b5560a38c07ef6f6b3c70be (MD5) Previous issue date: 2013-01-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The composites manufactured with long fibres aligned in a single direction, and overlay has been shown to have better performance than the short fibers randomly distributed. In particular, the lignocellulosic fibers extracted from the sisal leaves, used in conjunction with the epoxy resin has attracted the attention of many researchers because the final properties of the system formed. In this work composites based on epoxy resin reinforced with sisal fibers were manufactured. The sisal fibres were treated with an alkaline solution of 0.06 mol/l NaOH. The treated, and untreated fibres were subjected to tension x extension tests. The composites were manufactured in the "Lossy" mold with the specifications of the samples to be produced (300x20x4 mm). The tension tests were carried out in accordance with the ASTM standards 3039 (for the composite aligned in a single direction) and ASTM D5573 (for composites in overlay), three point bending tests were performed according to ASTM D790. Analyzing the results of the tests of tension and three point bending tests, it was observed that the composites with the configuration of overlapping had the better elastic module in both tests. As to the maximum resistance to tension, the best result was the composites aligned in a single direction. Tests of absorption of water and micrographs are in progress / Os comp?sitos fabricados com fibras longas alinhadas unidirecionalmente e em sobreposi??o tem demonstrado que possuem melhor desempenho do que as fibras cortadas aleatoriamente distribu?das. Em especial, as fibras lignocelul?sicas extra?das do sisal, utilizadas em conjunto com a resina ep?xi tem atra?do a aten??o de muitos pesquisadores devido ?s propriedades finais do sistema formado. No presente trabalho foram fabricados comp?sitos ? base de resina ep?xi refor?ado com fibras de sisal. As fibras de sisal foram submetidas ao tratamento alcalino com NaOH a 0,06 mol/l, em seguida submetidas ao ensaio de tra??o na fibra tratada e n?o tratada. Os comp?sitos foram fabricados no molde denominado de Lossy (molde com perdas) usinado de acordo com as especifica??es das amostras a serem produzidas (300x20x4 mm). Os ensaios de tra??o foram realizados de acordo com as normas ASTM 3039 (Para os comp?sitos alinhados unidirecionalmente) e ASTM D5573 (Para os comp?sitos em sobreposi??o), os ensaios de flex?o em tr?s pontos foram realizados de acordo com as normas ASTM D 790. Analisando os resultados dos ensaios de tra??o e flex?o em tr?s pontos, foram observados que os comp?sitos com a configura??o de sobreposi??o teve melhor m?dulo de elasticidade em ambos os ensaios. Quanto a resist?ncia m?xima a tra??o o melhor resultado foi do comp?sito alinhado unidirecionalmente. No ensaio de absor??o de ?gua foi observado que os comp?sitos possuem um n?vel muito baixo de absor??o e o comp?sito alinhado unidirecionalmente obteve percentual de satura??o de 1,97 %. Nas micrografias, se observa as regi?es de ruptura/trincas do comp?sito e seu comportamento (fibra/matriz)

[pt] A busca por materiais alternativos que possam substituir as fibras de amianto, compondo o fibro-cimento, tem-se tornado objeto de estudos recorrentes. As fibras vegetais surgem como opção econômica, salubre e ecologicamente adequada. O objetivo deste trabalho foi estudar o comportamento da adição da fibra de curauá em compósitos cimentícios, visando substituir o amianto. Essa fibra mineral é bastante conhecida pelos danos que provoca à saúde humana, já tendo sido banida em muitos países industrializados. Desde 1979, o Grupo de Pesquisas em Materiais não Convencionais da PUC-Rio tem desenvolvido trabalhos sobre a aplicação das fibras vegetais, disponíveis em abundância no Brasil, na fabricação de componentes para a construção civil, visando, principalmente, a produção de habitação popular. A fibra de curauá é de uso popular, na região conhecida como Baixo- Amazonas, oeste do Estado do Pará, na manufatura de cordas, cestas e tapetes, já existindo os primeiros plantios em escala comercial. Pouco conhecida nas demais regiões do país, a fibra de curauá ainda carece de estudos específicos sobre suas propriedades físicas, químicas e mecânicas, que possibilitem sua aplicação segura em compósitos para a construção civil. Nesse trabalho, foram estudadas as propriedades físicas, mecânicas e microestruturas das fibras de curauá, bem como de compósitos cimentícios que as tiveram como reforço. Buscou-se comparar o desempenho das fibras de curauá e de seus compósitos, com as fibras e compósitos de amianto e de outras fibras vegetais, tais como sisal, coco e juta. Os dados das fibras de sisal e coco, tomados para efeito de comparação, foram oriundos de trabalhos anteriores do mesmo grupo de pesquisas da PUC-Rio. Para as fibras de juta e compósitos cimentícios com reforço de juta e de sisal, foram obtidos dados através de ensaios realizados no escopo desse trabalho. Os resultados mostraram que a fibra de curauá possui características físicas e mecânicas que as habilitam à aplicação como reforço de matrizes cimentícias, principalmente quando for almejada uma maior ductilidade e capacidade de resistência após a fissuração da matriz. / [en] In recent years, there has been an intense search worldwide for an alternative material, which can substitute the asbestos fibre, a component of the asbestos cement, which has been found to be hazardous to human and animal health and has been banned already in many countries. Since 1979 the Non- conventional Materials Research Group of PUC-Rio has carried out works on the application of vegetable fibres, available in abundance in Brazil, for the fabrication of construction components, aiming mainly at the fabrication of popular housing. The curaúa fibre has been studied as it is already of popular use in the manufacturing of ropes, baskets and carpets in the region, known as Baixo Amazonas, in the state of Para, where the first plantations have been organized on a commercial scale. In this work, the physical, mechanical and micro-structural properties of the curauá fibres, as well as their application as a cimenticious matrix reinforcement, have been studied. The performance of curauá fibres and its composites was compared with other vegetable fibres, such as sisal, coconut and jute, as a substitute for asbestos fibres and its composites. The data on sisal and coconut fibres from previous works by the same research group at PUC-Rio was considered for comparison. The behaviour of jute fibres, as well as cimenticious composites, reinforced with jute and sisal fibres, have also been studied in this work. The results have shown that the curauá fibre has good physical and mechanical characteristics that make it suitable to be used as reinforcement of cimenticious matrices, with a high ductility and post-cracking resistance capacity.

M. Tech. (Department of Mechanical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / Sisal is a vegetable fibre extracted from the leaves of Agave Sisalana. The fibre is long, bold and creamy white in colour besides being exceptionally strong. It can be used for making agricultural and parcelling twines of various kinds as well as ropes, sacks, carpet and upholstery. The primary purpose of this research was to study and evaluate the use of sisal as a reinforcing fibre in both treated and untreated forms with epoxy resin matrices. The casting process employed during the composite production was the the vacuum infusion. The effects of both the treated sisal fibre-epoxy resin composites and the untreated sisal fibre-epoxy resin composites on the tensile strength and stiffness, flexural strength and stiffness, impact toughness, shear strength, compression strength and hardness were evaluated. Finally, the occurrence of transverse matrix fracture and fibre pull-out were also studied. It was found that the quasi-static mechanical properties of both the treated sisal fibre-epoxy resin composites and the untreated sisal fibre-epoxy resin composites improved with increases in reinforcement weight fractions. Further, fibre surface treatment on the sisal fibres and the attendant increase in the interfacial bond also resulted into improved quasi-static mechanical properties of the treated sisal fibre-epoxy resin composites when compared to untreated sisal fibre-epoxy resin composites.