Nanocompósitos de epóxi/nanopartículas de carbonato de cálcio: propriedades termomecânicas e de superfície

• Ano de defesa: 2019
• Autor(a) principal: Thaís Bastos Miranda
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ENG - DEPARTAMENTO DE ENGENHARIA QUÍMICA; Programa de Pós-Graduação em Engenharia Química; UFMG
• Palavras-chave em Português: Nanopartículas de CaCO3; Epóxi; Compósitos; Estrutura hierárquica; Método mecanoquímico; Engenharia química; Carbonato de cálcio; Nanopartículas; Resinas epóxi
• Link de acesso: http://hdl.handle.net/1843/30101

Continuous demand for highly efficient materials encourages innovations on nanotechnology and nanocomposites manufacturing. The addition of calcium carbonate to epoxy resin may reduce production costs and improve the polymer’s performance. Therefore, in this study, calcium carbonate nanoparticles were synthesized by mechanochemical processing and epoxy/nano CaCO3 composites were produced aiming to obtain materials with enhanced thermomechanical and surface properties with respect to the neat epoxy. Calcium carbonate nanoparticles of calcite structure and nanometric size were successfully synthesized by mechanochemical processing using low energy mill (100 rpm). The incorporation of calcium carbonate nanoparticles at concentrations of 1, 2.5, 3 and 5 wt.% to epoxy resin DGEBA resulted in thermally stable composites. Epoxy/2.5 wt.% and epoxy/3 wt.% composites displayed an increase of 12°C and 14°C in glass transition temperature (Tg), respectively. Scanning electron microscopy images of composites revealed a hierarchical structure of micrometric sized extended aggregates of nanometric calcium carbonate particles homogeneously distributed in the polymer matrix. This morphology explains the increase in hydrophobicity, as well as gains in Young’s moduli, which were greater than 59% with respect to the neat epoxy as measured by Nanoindentation.