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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

Aproveitamento da fibra do epicarpo do coco baba?u em comp?sito com matriz ep?xi: estudo do efeito do tratamento da fibra

Franco, Francisco Jos? Patr?cio 07 August 2010 (has links)
Made available in DSpace on 2014-12-17T14:06:55Z (GMT). No. of bitstreams: 1 FranciscoJPF.pdf: 1681554 bytes, checksum: 4238148885bafd3e26a8d8ca7de20466 (MD5) Previous issue date: 2010-08-07 / Nowadays the environmental issues are increasingly highlighted since the future of humanity is dependent on the actions taken by man. Major efforts are being expended in pursuit of knowledge and alternatives to promote sustainable development without compromising the environment. In recent years there has been a marked growth in the development of reinforced composite fiber plants, as an alternative for economic and ecological effects, especially in the substitution of synthetic materials such as reinforcement material in composites. In this current study the chemical- physical or (thermophysics )characteristics of the babassu coconut fiber, derived from the epicarp of the fruit (Orbignyda Phalerata), which the main constituents of the fiber: Klason lignin, insoluble, cellulose, holocellulose, hemicellulose and the content of ash and moisture will be determined. A study was conducted about the superficial modification of the fibers of the epicarp babassu coconut under the influence of chemical treatment by alkalinization, in an aqueous solution of NaOH to 2.5% (m/v) and to 5.0% to improve the compatibility matrix / reinforcement composite with epoxy matrix. The results of the changes occurred in staple fibers through the use of the techniques of thermogravimetric analyses (TG) and differential scanning calorimetry (DSC). The results found on thermal analysis on samples of fiber without chemical treatment (alkalinities), and on fiber samples treated by alkalinization show that the proposed chemical treatment increases the thermal stability of the fibers and provides a growth of the surface of area fibers, parameters that enhance adhesion fiber / composite. The findings were evaluated and compared with published results from other vegetable fibers, showing that the use of babassu coconut fibers has technical and economic potential for its use as reinforcement in composites / Atualmente as quest?es ambientais ganham destaque cada vez mais acentuado, j? que o futuro da humanidade est? dependente das a??es tomadas hoje pelo homem. Grandes esfor?os est?o sendo despendidos na busca de conhecimentos e solu??es alternativas sustent?veis que promova o desenvolvimento sem comprometimento do meio ambiente. Nos ?ltimos anos tem havido um crescimento acentuado no desenvolvimento de comp?sitos refor?ados por fibras vegetais, como uma alternativa econ?mica e ecol?gica, principalmente, na substitui??o de materiais sint?ticos, como material de refor?o em comp?sitos. No presente trabalho foram analisadas as caracter?sticas qu?mico-f?sicas de fibra oriundas do epicarpo do coco baba?u (Orbignyda Phalerata), sendo determinados os principais teores dos constituintes da fibra: lignina Klason insol?vel, celulose, holocelulose, hemicelulose e os teores de cinzas e de umidade. Foi realizado um estudo da modifica??o superficial das fibras do epicarpo do coco baba?u sob efeito de tratamento qu?mico por alcaliniza??o, em solu??o aquosa de NaOH a 2,5% (m/v) e a 5,0% (m/v), visando melhorar a compatibiliza??o matriz/refor?o em comp?sito com a matriz de ep?xi. Os resultados das modifica??es ocorridas nas fibras foram estudados atrav?s de t?cnicas de termogravimetria (TG) e de calorimetria explorat?ria diferencial (DSC). Os resultados encontrados nas an?lises t?rmicas em amostras de fibras sem tratamento qu?mico e em amostras de fibras tratadas por alcaliniza??o mostram que o tratamento qu?mico proposto aumentou a estabilidade t?rmica das fibras e proporcionou um crescimento na ?rea superficial das fibras, par?metros que melhoram a ades?o fibra/comp?sito. Os resultados obtidos foram avaliados e comparados com resultados publicados de outras fibras vegetais, mostrando que a utiliza??o das fibras de coco baba?u tem potencialidades t?cnicas e econ?micas para o seu uso como refor?o de comp?sitos

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