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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

SÃntese, caracterizaÃÃo e funcionalidade de aditivos de lubricidade, derivados do LLC. / The syntesis, characterization and functionality of lubrificant additives, derivates of the LLC.

Lincoln Davi Mendes de Oliveira 27 March 2007 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Este trabalho relata a sÃntese, caracterizaÃÃo e anÃlise de compostos fosforados com potencial lubrificante, obtidos a partir do LCC, um subproduto da indÃstria de processamento da castanha. Os quatro compostos sintetizados [Dietil-3-n-pentadecilfenol tiofosfato (1), Dietil-3-n-pentadecilfenol fosfato (2), Difenil-3-n-pentadecilfenol fosfato (3) e Tri-3-n-pentadecilfenol fosfato (4)] utilizaram como precursor o 3-n-pentadecilfenol (cardanol hidrogenado) e foram caracterizados por um conjunto de tÃcnicas experimentais (RMN 1H, 13C e 31P, infravermelho e CG/EM) que revelaram a pureza dos mesmos. A estabilidade tÃrmica dos compostos foi verificada atravÃs de vÃrios estÃgios de degradaÃÃo tÃrmica. Os compostos (1) e (2) sÃo menos estÃveis que (3) e (4), no entanto, todos eles apresentaram-se dentro da faixa da temperatura de degradaÃÃo para os aditivos de lubricidade comerciais similares. A estabilidade oxidativa foi avaliada utilizando mÃtodo do oxigÃnio ativo. Todos os Ãleos aditivados apresentaram diminuiÃÃo no Ãndice de acidez caracterizando-os como potenciais antioxidantes, especialmente no que se refere à relaÃÃo custo/benefÃcio, fator importante na escolha de um aditivo ressaltando-se o excelente desempenho do composto (1). A anÃlise do potencial lubrificante revelou diminuiÃÃo no desgaste das esferas cobertas com os Ãleos aditivados quando comparados ao padrÃo (sem aditivo). O teste de lubricidade revelou que todos compostos encontram-se dentro dos parÃmetros exigidos pela legislaÃÃo em vigor na concentraÃÃo de 2%. / This work repots the synthesis, characterization and analysis of the phosphorous compounds with lubricant potential, obtained from CNSL, a byproduct of cashew nut processing industries. The four synthesized compounds [Diethyl-3-n-pentadecylphenol thiophosphate (1), Diethyl-3-n-pentadecylphenol phosphate (2), Diphenil-3-n-pentadecylphenol phosphate (3) and Tri-3-n-entadecylphenol phosphate (4)] used 3-npentadecylphenol (hydrogenated cardanol) as forerunner and were characterized by spectroscopic techniques (NMR 1H, 13C and 31P, infrared and GC/MS) that revealed their purity. The thermal stability of all compounds was verified by several steps of thermal degradation. Compounds (1) and (2) were less stable than (3) and (4), but, all of them showed degradation temperatures in the similar range of commercial lubricity additives. The oxidative stability was evaluated using the active oxygen method. All the additivated oils showed a decreasing in the acid scale , characterizing the compounds as potential antioxidants, especially relative to the cost/benefit ratio, emphasizing the excellent performance of the compound. The analysis of the lubricant potential revealed a diminution in the wear of the spheres covered with additivated oils when compared to the standard (without additive). The test of lubricity revealed that all compounds are inside the parameters required by the present legislation in the concentration of 2 %.

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