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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

PainÃis de fibras elaboradas a partir da casca do coco verde sem adiÃÃo de resinas aglutinantes / Fiberboards from coconut husk without addiction of synthetic resins

Celso Pires de AraÃjo JÃnior 08 April 2014 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O consumo crescente da Ãgua de coco gera uma grande quantidade de resÃduo de difÃcil gerenciamento. O aproveitamento dessa biomassa reduz o acÃmulo de resÃduos, agrega valor à cadeia produtiva, gera renda e aumenta a vida Ãtil dos aterros sanitÃrios. Uma possibilidade à utilizar a casca de coco verde na manufatura de painÃis como alternativa aos painÃis elaborados com madeira. Uma das vantagens do uso da casca de coco à seu alto teor de lignina, que sob condiÃÃes adequadas de pressÃo e temperatura, pode funcionar como um ligante natural dispensando o uso de resinas sintÃticas para aglutinar as fibras. Em geral, essas resinas sÃo formuladas com formaldeÃdo, substÃncia derivada do petrÃleo e potencialmente causadora de cÃncer. A partir desses painÃis, à possÃvel fabricar mÃveis, divisÃrias, pisos e revestimentos sem a necessidade de efetuar o corte de espÃcies florestais. O presente trabalho teve como objetivo obter e caracterizar painÃis lignocelulosicos, utilizando como matÃria- prima as fibras e o pà da casca do coco verde, sem adiÃÃo de resinas sintÃticas. Os painÃis obtidos foram submetidos a anÃlises tÃrmicas, testes de inchamento em espessura, absorÃÃo de Ãgua, ensaios mecÃnicos, caracterizaÃÃo por infravermelho e microscopia eletrÃnica de varredura. De acordo com os resultados obtidos, a lignina presente naturalmente na matÃria- prima atuou como ligante, sendo possÃvel obter painÃis com boa integridade estrutural. Todos os painÃis apresentaram valores de absorÃÃo de Ãgua inferiores ao MDF comercial. Alguns painÃis apresentaram mÃdulo de elasticidade superior ao MDF comercial. / The growing consumption of coconut water leads to high volumes of tough management wastes. The use of this biomass adds value to the supply chain, reduces the amount of waste, increases the financial income, and extends the service life of landfills. An option to use the coconut biomass is manufacturing plywood panels as an alternative to wood plywood boards. Coconut husk has a comparative advantage in relation to the wood plywood: a high content of lignin, which under certain pressure and temperature conditions can act as a natural binder, dispensing synthetic bonding resins to aglutinate the fibers. Usually the resins are made with formaldehyde, an oil-derived chemical and potential cause of cancer. Plywood can be used to manufacture furniture, wall panels, and floor bases, without cutting down trees. The aim of this work was to produce and characterize lignocellulosic panels made with unripe coconut husk fiber and pith, with no adding of synthetic resins. The boards were characterized by thermal analysis, thickness swelling tests, water absorption, mechanical testing, FTIR spectroscopy, and scanning electron microscopy. As expected, there was a significant correlation between the degradation of the main chemical constituents of the raw material and the final characteristics of the panels. According to the results, the lignin naturally present in the feedstock acted as a binder, it is possible to obtain panels with good structural integrity. All panels showed values of water absorption lower than the commercial MDF. Some panels showed higher elastic modulus to the commercial MDF.

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