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Master's Dissertation
DOI
https://doi.org/10.11606/D.18.2022.tde-19122022-120810
Document
Author
Full name
Ana Yenny Molleapaza Tito
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 2022
Supervisor
Committee
Tarpani, José Ricardo (President)
Paiva, Jane Maria Faulstich de
Santos Neto, Álvaro José dos
Title in Portuguese
Estudo do comportamento higrotérmico de nanocompósitos de resina epóxi contendo celulose microfibrilada
Keywords in Portuguese
celulose microfibrilada
degradação higrotérmica
nanocompósitos
resina epóxi
Abstract in Portuguese
Neste estudo, nanocompósitos de resina epóxi foram manufaturados com diferentes conteúdos de celulose microfibrilada fornecida na forma aquosa, nas concentrações mássicas de 0,5%, 0,75% e 1%. Empregou-se na síntese deles dois distintos solventes, quais sejam, acetona e álcool isopropílico com o objetivo de melhor dispersar a celulose e evitar os efeitos nocivos da água na cura da resina. Os materiais foram imersos em água aquecida por um período de seis meses de modo a promover o envelhecimento higrotérmico e afetar suas propriedades físico- químicas. Ensaios e análises por gravimetria, espectroscopia do infravermelho, termogravimetria, calorimetria exploratória diferencial e dureza Vickers foram conduzidos para avaliar o efeito do teor de celulose no comportamento de degradação dos nanocompósitos de matriz epóxi, assim como para revelar os mecanismos operantes. Verificou-se que o emprego de acetona como solvente é mais adequado que o álcool isopropílico na manutenção das propriedades originais dos nanocompósitos, o que foi particularmente verdadeiro para um conteúdo de 0,75% de celulose microfibrilada.
Title in English
Study of the hygrothermal behavior of epoxy resin nanocomposites containing microfibrillated cellulose
Keywords in English
epoxy resin
hygrothermal degradation
microfibrillated cellulose
nanocomposites
Abstract in English
In this study, epoxy resin nanocomposites were manufactured with varying amounts of microfibrillated cellulose supplied in aqueous form, at mass concentrations of 0.5%, 0.75%, and 1%. Two different solvents, acetone and isopropyl alcohol, were used in their synthesis with the goal of better dispersing the cellulose and avoiding the harmful effects of water on resin curing. For six months, the materials were immersed in hot water to promote hygrothermal aging and affect their physicochemical properties. Gravimetry, infrared spectroscopy, thermogravimetry, differential scanning calorimetry, and Vickers hardness tests were performed to assess the effect of cellulose content on the degradation behavior of epoxy matrix nanocomposites and to uncover the operative mechanisms. It was discovered that using acetone as a solvent is more suitable than using isopropyl alcohol in maintaining the original properties of the nanocomposites, which was especially true for a 0.75 % microfibrillated cellulose content.
 
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Publishing Date
2022-12-20
 
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