Polyurethane Foams
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. Production of Carbon Foams from Rice Husk
The production of a material with rigid, multifunctional three-dimensional porous structure at a low cost is still challenging to date. In this work, a light and rigid carbon foam was prepared using rice husk as the basic element through a simple fermentation process followed by carbonization. For the fermentation process, the amount of biological yeast (7.5
Mat. Res.. Publicado em: 11/11/2019
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2. ESTUDO CINÉTICO DE DECOMPOSIÇÃO TÉRMICA DE ESPUMAS RÍGIDAS DE POLIURETANO POR REDE NEURAL ARTIFICIAL
Kinetic models of solid thermal decomposition are traditionally used for individual fit of isothermal experimental data. However, this methodology presents unacceptable errors in some regions of the data. To solve this problem, a neural network was adopted in this work. The implemented algorithm uses the rate constants as predetermined weights between the in
Quím. Nova. Publicado em: 2017-10
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3. SYNTHESIS, CHARACTERIZATION AND APPLICATION OF A POLYURETHANE-BASED SUPPORT FOR IMMOBILIZING MEMBRANE-BOUND LIPASE
Abstract This study conducted an assessment of polyurethane foams that were synthesized by one-shot process and used as a low-cost support to immobilize Mucor circinelloides URM 4182 whole-cells presenting high lipolytic activity. Polyols with different molecular weights (1100 to 6000 g mol-1) were applied to synthesize the polymer matrix, and the agitation
Braz. J. Chem. Eng.. Publicado em: 2017-01
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4. Preparation of novel magnetic polyurethane foam nanocomposites by using core-shell nanoparticles
Abstract Iron oxide magnetic nanoparticles (NP's) converted to the core- shell structres by reacting with by n-(2-aminoethyl)-3-aminopropyl trimethoxysilane (AEAP) incorporated in polyurethane flexible (PUF) foam formulations. Fourier transform spectra, thermal gravimetric analysis, scanning electron images, thermo-mechanical analysis and magnetic properties
Polímeros. Publicado em: 08/12/2016
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5. Using different catalysts in the chemical recycling of waste from flexible polyurethane foams
Due to their versatility, polyurethane (PU) foams have many different applications, such as sponges, filling materials in furniture, automotive seats and clothes, among others. It is also one of the main refrigerator components serving as a heat insulating material. As PUs find different application niches, they must be largely produced and, consequently, lo
Polímeros. Publicado em: 25/10/2013
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6. Produção e caracterização de espumas cerâmicas obtidas a partir de lodo de anodização de alumínio
Ceramic foams were produced from a sludge generated in the aluminum anodizing process by using an industrial polyurethane foam (replication method) with open cell sizes of 10 ± 5 ppi (porosity = 97%) which were impregnated with suspensions containing 50-61 wt.% alumina, 1 wt.% citric acid, 6 wt.% bentonite and fired at 1600 ºC for 2 h. The aluminum anodizi
Química Nova. Publicado em: 2012
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7. Síntesis de espumas rígidas de poliuretano obtenidas a partir de aceite de castor y poliglicerol empleando calentamiento por microondas
In this work we showed the polyurethane rigid foams synthesis using a macropolyol synthesized from castor oil and polyglycerol. This process is optimized employing a response surface analysis and using a 3² factorial design. The factors evaluated were: amount of water and tartaric acid, where tartaric acid acts as crosslinking agent and catalyst; mechanical
Polímeros. Publicado em: 11/02/2011
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8. Tecnologia assistiva : personalização em massa através do design e fabricação de assentos customizados para cadeiras de rodas
The design of customized seats manufactured in polyurethane foams is and alternative to improve comfort and positioning for people with disabilities, as those people spend hours of the day seated in the same position. These support surfaces increase the contact area between the seat and user. This aspect improves weight distribution reducing localized pressu
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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9. Reciclagem química de espumas de poliuretano / Chemical recycling of polyurethane foams
Os poliuretanos representam uma variedade de produtos caracterizados pela presença de grupos carbamatos na cadeia principal, formados através da reação de poliadição dos compostos isocianatos com outros contendo hidrogênio ativo, assim como os alcoóis. São utilizados em diversas áreas e constituem um dos mais importantes grupos de polímeros devido
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/02/2010
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10. Síntesis y caracterización de espumas flexibles de poliuretano obtenidas a partir de aceite de castor maleinizado
In this work, the synthesis of polyurethane flexible foam is realized with the experimental design Taguchi, using castor oil with and without maleinization. The kinetic reaction of oil esterification was monitored by estimating the number of acid groups (ASTM D4662 - 03), and the mechanical properties of the foam were studied, including density, tensile resi
Polímeros. Publicado em: 2009-06
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11. Obtenção e caracterização de espumas cerâmicas de alumina para uso como queimadores radiantes
Ceramic foams are cellular porous ceramics that can be produce by different methods, like replica method, sacrificial template method and direct foaming method. Foams are a type of porous ceramic which present many properties making them a very versatile material, used in different applications, like radiant porous burners. Radiant burners consist of ceramic
Publicado em: 2009
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12. Remoção de corantes em efluentes têxteis utilizando espumas de poliuretano e resíduos de sementes de Mabea fistulifera Mart. / Dye removal in textile effluents using polyurethane foams and residues of Mabea fistulifera Mart.
The absorption is successfully used in removing the organic contaminants found in textile effluent. This work proposes the use of alternative absorbents to remove the direct dyes (Direct Red 80) and reactive (Reactive Blue 21) in aqueous solutions and in effluent samples. Two absorbents were tested: the synthetic polyurethane foams (EPUs) and the seed residu
Publicado em: 2009