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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 do aproveitamento de res?duo de gesso como carga para comp?sito com matriz de resina expansiva de mamona

Oliveira Neto, Manoel Leonel de 16 February 2012 (has links)
Made available in DSpace on 2014-12-17T14:57:53Z (GMT). No. of bitstreams: 1 ManoelLON_TESE.pdf: 2837089 bytes, checksum: 962b0c298a9cc0d199caa357de4ce608 (MD5) Previous issue date: 2012-02-16 / In the execution of civil engineering works, either by wasting during the coating of wall or demolition of gypsum walls, the generation of the gypsum waste involves serious environmental concerns. These concerns are increased by the high demand of this raw material in the sector and by the difficulties of proper disposal byproduct generated. In the search for alternatives to minimize this problem, many research works are being conducted, giving emphasis in using gypsum waste as fillers in composites materials in order to improve the acoustic, thermal and mechanical performances. Through empirical testing, it was observed that the crystallization water contained in the residue (CaSO4.2H2O) could act like primary agent in the expanding of the polyurethane foam. Considering that polyurethane produced from vegetable oils are biodegradable synthetic polymers and that are admittedly to represent an alternative to petrochemical synthetic polyurethane, this research consist an analysis of the thermal behavior of a composite whose matrix obtained from a resin derived from the expansive castor oil seed, with loads of 4%, 8%, 12% and 16% of gypsum waste replacing to the polyol prepolymer blend. Contributors to this analysis: a characterization of the raw material through analysis of spectroscopy by Fourier transform infrared (FTIR), chemical analysis by X-Ray Fluorescence (XRF) and mineralogical analysis by X Ray Diffraction (XRD), complemented by thermo gravimetric analysis (TGA). In order to evaluate the thermo physical properties and thermal behavior of the composites manufactured in die closed with expansion contained, were also carried tests to determine the percentage of open pore volume using a gas pycnometer, scanning electronic microscopy (SEM), in addition to testing of flammability and the resistance to contact with hot surfaces. Through the analysis of the results, it appears that it is possible to produce a new material, which few changes in their thermo physical properties and thermal performance, promotes significant changes and attractive to the environment / Na execu??o de obras na constru??o civil, seja por desperd?cio de gesso durante o revestimento de paredes ou na demoli??o de paredes de gesso acartonado, a gera??o do res?duo implica em preocupa??es ambientais decorrentes da alta demanda dessa mat?ria prima no setor e da dificuldade de destina??o adequada ao subproduto gerado. Na busca por uma alternativa que atenue o problema, muitas pesquisas t?m sido realizadas com ?nfase na utiliza??o do res?duo de gesso como carga em comp?sitos, com o intuito de melhorar os desempenhos ac?stico, t?rmico e mec?nico. Atrav?s de ensaios emp?ricos, observou-se que a ?gua de cristaliza??o contida no res?duo (CaSO4.2H2O) pode atuar como agente prim?rio no processo de expans?o de espumas de poliuretano. Considerando que os poliuretanos, derivados de ?leos vegetais, s?o pol?meros sint?ticos biodegrad?veis e que, reconhecidamente, representam uma alternativa aos poliuretanos sint?ticos petroqu?micos, a presente pesquisa procura fazer uma an?lise do comportamento t?rmico de um comp?sito desenvolvido com matriz de resina vegetal derivada do ?leo de mamona, com cargas de 4%, 8%, 12% e 16% de res?duo de gesso em substitui??o ? mistura poliol + pr?-pol?mero. Contribu?ram para esta an?lise: caracteriza??o da mat?ria prima por meio de espectroscopia de absor??o na regi?o do infravermelho por transformada de Fourier (FTIR), an?lise qu?mica por FRX e mineral por DRX e an?lise termogravim?trica (TGA e DTA). Com o prop?sito de avaliar as propriedades termof?sicas e o comportamento t?rmico dos comp?sitos produzidos com expans?o contida por fechamento do molde. Tamb?m foram realizados ensaios para determina??o do percentual de poros abertos, por meio de picn?metro a g?s, morfologia dos comp?sitos (MEV), al?m de ensaios de inflamabilidade e de resist?ncia ao contato com superf?cies aquecidas. Mediante a an?lise dos resultados obtidos, constatou-se a possibilidade de produ??o de um novo material para isola??o t?rmica, apresentando poucas altera??es em suas propriedades Termof?sicas, assim como em seu desempenho t?rmico, promovendo altera??es significativas e atraentes ao meio ambiente

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