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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Fibras de licuri: um refor?o vegetal alternativo de comp?sitos polim?ricos

Le?o, Mirt?nia Antunes 27 September 2009 (has links)
Made available in DSpace on 2014-12-17T14:57:46Z (GMT). No. of bitstreams: 1 MirtaniaAL.pdf: 1813042 bytes, checksum: 3d26a66f383220285205f479f11b4656 (MD5) Previous issue date: 2009-09-27 / This research is based, at first, on the seeking of alternatives naturals reinforced in place of polymeric composites, also named reinforced plastics. Therein, this work starts with a whole licuri fiber micro structural characterization, as alternative proposal to polymeric composites. Licuri fiber is abundant on the Bahia state flora, native from a palm tree called Syagrus Coronata (Martius) Beccari. After, it was done only licuri fiber laminar composite developing studies, in order to know its behavior when impregnated with thermofix resin. The composite was developed in laminar structure shape (plate with a single layer of reinforcement) and produced industrially. The layer of reinforcement is a fabric-fiber unidirectional of licuri up in a manual loom. Their structure was made of polyester resin ortofit?lica (unsaturated) only reinforced with licuri fibers. Fiber characterization studies were based on physical chemistry properties and their constitution. It was made by tension, scanning electron microscopy (SEM), x-ray diffraction (RDX) and thermal analyses (TG and DTA) tests, besides fiber chemistry analyses. Relating their mechanical properties of strength and hardness testing, they were determined through unit axial tension test and flexion in three points. A study in order to know fiber/matrix interface effects, in the final composites results, was required. To better understand the mechanical behavior of the composite, macroscopic and microscopic optical analysis of the fracture was performed / Esta investiga??o baseia-se, em principio, na busca de refor?os naturais alternativos aos comp?sitos polim?ricos, tamb?m denominados de pl?sticos refor?ados. Neste sentido, o presente trabalho de pesquisa se inicia com um completo estudo de caracteriza??o micro estrutural da fibra de licuri, essa como proposta alternativa de refor?o aos comp?sitos polim?ricos. A fibra de licuri ? abundante na flora do estado da Bahia e origin?ria da palmeira denominada Syagrus Coronata (Martius) Beccari. Em seguida, foi realizado um estudo do desenvolvimento de um comp?sito laminar somente a base de fibras de licuri, de forma a se conhecer o comportamento da fibra quando impregnada com resina termofixa. O comp?sito foi desenvolvido na forma de estrutura laminar (placa com uma ?nica l?mina de refor?o) e fabricado industrialmente. A l?mina de refor?o ? de um tecido unidirecional de fibras de licuri confeccionado em um tear manual. O comp?sito tem em sua estrutura resina poli?ster ortofit?lica (insaturada) refor?ada somente com fibras de licuri. O estudo da caracteriza??o da fibra teve como base a determina??o das propriedades f?sicas, qu?micas e de constitui??o. As mesmas foram realizadas atrav?s dos ensaios de: tra??o uniaxial, an?lise por microscopia eletr?nica de varredura (MEV), ensaio de difra??o de raios X (RDX), an?lises t?rmicas (TG e DTA), al?m da an?lise qu?mica das fibras. Com rela??o ?s propriedades mec?nicas de resist?ncia e rigidez do comp?sito, estas foram determinadas atrav?s dos ensaios de tra??o uniaxial e flex?o em tr?s pontos. Um estudo com o objetivo de conhecer a influ?ncia da ader?ncia da interface fibra/matriz, na resposta final do comp?sito, se fez necess?rio. Para melhor entendimento do comportamento mec?nico do comp?sito, an?lises macrosc?picas e microsc?picas ?pticas da fratura foram realizadas

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