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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

Estudo dos comp?sitos de PURM com rejeitos do porcelanato e da Scheelita para aplica??es em isolantes t?rmicos

Galv?o, ?lvaro C?sar Pontes 18 January 2018 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-03-20T17:21:11Z No. of bitstreams: 1 AlvaroCesarPontesGalvao_TESE.pdf: 6716777 bytes, checksum: df8fe317e5a0a57cfab2282907650b26 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-03-22T12:13:19Z (GMT) No. of bitstreams: 1 AlvaroCesarPontesGalvao_TESE.pdf: 6716777 bytes, checksum: df8fe317e5a0a57cfab2282907650b26 (MD5) / Made available in DSpace on 2018-03-22T12:13:19Z (GMT). No. of bitstreams: 1 AlvaroCesarPontesGalvao_TESE.pdf: 6716777 bytes, checksum: df8fe317e5a0a57cfab2282907650b26 (MD5) Previous issue date: 2018-01-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A utiliza??o de uma espuma de poliuretano proveniente de uma fonte renov?vel, como ? o caso da espuma poliuretano de mamona e adi??o de cargas rejeitos t?o abundantes no Nordeste (scheelita e gr?s porcelanato), representaria uma redu??o do consumo de espuma de origem exaur?vel. Sendo assim, verifica-se a necessidade de estudos relativos ao desempenho termof?sico/mec?nico de comp?sitos desta espuma com rejeitos do beneficiamento da scheelita e do polimento do gr?s porcelanato para fins de isola??o t?rmica. Esta pesquisa objetivou desenvolver comp?sitos de poliuretano de mamona (PURM) com cargas de rejeitos de porcelanato (PRP) e scheelita (PRS) que possam ser utilizados como isolantes t?rmicos alternativos, visando ? redu??o de custos e consumo de mat?ria-prima, al?m de contribuir com o desenvolvimento sustent?vel dessas ind?strias. No estudo utilizou-se micropart?culas PRS e PRP para o desenvolvimento e caracteriza??o de comp?sitos de PURM. Estes comp?sitos foram caracterizados termofisicamente a partir de ensaios de condutividade t?rmica, calor espec?fico, difusividade t?rmica e termogravimetria. Propriedades como massa espec?fica, resist?ncia ? compress?o e dureza tamb?m foram analisadas nos comp?sitos PURM+PRS e PURM+ PRP. As estruturas celulares destes comp?sitos de PURM foram analisadas pelas t?cnicas de MEV (Microscopia Eletr?nica de Varredura) com microan?lise qu?mica EDS (Espectroscopia por Energia Dispersiva de Raios X). Verificou-se que os melhores comp?sitos com propriedades isolantes foram PURM+5PRP125 e PURM+5PRP300-600 por possu?rem menor condutividade t?rmica. O mesmo ocorreu para os comp?sitos de PURM+5PRS, tamb?m para ambos os tamanhos de part?culas (125 ?m e entre 300 a 600 ?m). Entretanto, comparando a efici?ncia de isola??o t?rmica baseada nos menores valores de condutividade t?rmica e maior calor espec?fico, tem-se o comp?sito PURM+5PRP125 como o que apresentou um comportamento t?rmico mais pr?ximo ao do PURM-Puro e cuja isola??o t?rmica foi maior que a dos demais comp?sitos de PURM e tamb?m dos isolantes t?rmicos comerciais (l? de rocha, l? de vidro, EPS, etc.). / The use of a polyurethane foam from a renewable source, as the case of the foam from the castor oil and addition of waste (scheelite and porcelain stoneware) plentiful in the northeast region of Brazil, would represent a reduction of consume in limited source foam. Due to this, it is verified the necessity of studies concerning to the thermophysical/mechanical performance of this foam composites with both the scheelite processing and polishing porcelain stoneware wastes for thermal insulation purposes. This research aimed to develop composites of rigid polyurethane foam from ricin oil (PURM) with stoneware porcelain (PRP) and scheelite (PRS) waste which could be used as thermal insulation, aiming the reduction of costs and raw material consume; furthermore, to contribute with the sustainable development of these industries. In this study were used PRS and PRP microparticles for confection and characterization of PURM composites. These composites were thermophysical characterized with tests of thermal conductivity, specific heat, thermal diffusivity and thermogravimetry. Material properties such as density, compressive strength and hardness were also analyzed in the PURM+PRS and PURM+PRP composites. The cellular structures of these PURM composites were analyzed by MEV (Scanning Electron Microscopy) with chemical microanalysis EDS (Energy Dispersive X-Ray Spectroscopy). It was verified that the best composites with insulating properties were PURM+5PRP125 and PURM+5PRP300-600 because they had a lower thermal conductivity than other PURM composites. The same occurred for the PURM+5PRS composites, also for both particle sizes (125 ?m and between 300 and 600 ?m). However, comparing the thermal insulation efficiency based on the lower values of thermal conductivity and higher specific heat, the PURM+5PRP125 composite was the one which presented the closest thermal behavior value to PURM-Pure, likewise exhibited higher thermal insulation than the other PURM composites and the commercially available thermal insulators (rock wool, glass wool, EPS, and others).
2

Comp?sito de poliuretano de mamona e vermiculita para isola??o t?rmica / Composite polyurethane of mamona and vermiculite for thermal insulation

Silva, Jacques Cousteau da 23 January 2009 (has links)
Made available in DSpace on 2014-12-17T14:57:48Z (GMT). No. of bitstreams: 1 JacquesCSB.pdf: 3422358 bytes, checksum: 0481c21c9c3c217fb85970c2c726b768 (MD5) Previous issue date: 2009-01-23 / They are in this study the experimental results of the analysis of thermal performance of composite material made from a plant matrix of polyurethane derived from castor oil of kernel of mamona (COF) and loading of clay-mineral called vermiculite expanded. Bodies of evidence in the proportions in weight of 10%, 15% and 20% were made to determine the thermal properties: conductivity (k), diffusivity (ά) and heat capacity (C), for purposes of comparison, the measurements were also performed the properties of polyurethane of castor without charge and also the oil polyurethane (PU), both already used in thermal insulation. Plates of 0.25 meters of material analyzed were manufactured for use as insulation material in a chamber performance thermal coverage. Thermocouples were distributed on the surface of the cover, and inside the material inside the test chamber and this in turn was subjected to artificial heating, consisting of a bank of incandescent lamps of 3000 w. The results obtained with the composite materials were compared with data from similar tests conducted with the camera alone with: (a) of oil PU, (b) of COF (c) glass wool, (d ) of rock wool. The heat resistance tests were performed with these composites, obtaining temperature limits for use in the range of 100 ? C to 130 ? C. Based on the analysis of the results of performance and thermal properties, it was possible to conclude that the COF composites with load of expanded vermiculite present behavior very close to those exhibited by commercial insulation material / Apresentam-se nesta pesquisa os resultados experimentais obtidos da an?lise de desempenho t?rmico do material comp?sito confeccionado a partir de uma matriz vegetal de poliuretano derivado do ?leo de mamona e carga do argilo-mineral denominado vermiculita expandida. Corpos de provas nas propor??es em massa de 10%, 15% e 20% foram fabricados para determina??o das propriedades t?rmicas: condutividade (k), difusividade (ά) e capacidade calor?fica (C), para efeito de compara??o, tamb?m foram realizadas as medi??es de propriedades do poliuretano de mamona sem carga e tamb?m do poliuretano de petr?leo (PU), Ambos j? empregados em isolamento t?rmico. Placas de 0,25 m? dos materiais analisados foram fabricadas para uso como material de isola??o em uma c?mara de desempenho t?rmico de cobertura. Termopares foram distribu?dos na superf?cie da cobertura, no interior dos materiais e no interior da c?mara de teste e esta, por sua vez, foi submetida a aquecimento artificial, constitu?do por um banco de l?mpadas incandescentes de 3000 w. Os resultados obtidos com os materiais comp?sitos foram comparados com dados obtidos em ensaios id?nticos realizados com a c?mara isolada com: (a) poliuretano de petr?leo (PU); (b) poliuretano de ?leo de mamona; (c) l? de vidro; (d) l? de rocha. Testes de resist?ncia ao calor foram realizados com esses comp?sitos, obtendo temperaturas limites de uso na faixa de 100?C a 130 ?C. Com base na an?lise dos resultados de desempenho e propriedades t?rmicas, foi poss?vel concluir que os comp?sitos de poliuretano de mamona com carga de vermiculita expandida apresentam comportamentos muito pr?ximos daqueles exibidos pelos materiais de isola??o comerciais

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