Síntese, caracterização estrutural e propriedades térmicas do material híbrido poli(metilmetacrilato)/ferroxita: um estudo experimental e teórico

• Ano de defesa: 2016
• Autor(a) principal: Corrêa, Silviana
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Lavras; Programa de Pós-Graduação em Agroquímica; UFLA; brasil; Departamento de Química
• Palavras-chave em Português: Material híbrido; Ferroxita; PMMA; Nanocompósitos; Hybrid material; Feroxyhyte; DFT; Radical trapping; Nanocomposites; Polimeros e Colóides
• Link de acesso: http://repositorio.ufla.br/jspui/handle/1/10987

Feroxyhyte and polymethylmethacrylate - PMMA nanocomposites were prepared by grafting 3-(trimethoxy-silyl)propyl methacrylate onto the surface of iron oxide particles. We studied two hybrids with 0.5 and 2.5 wt% of feroxyhyte nanoparticles. The FTIR spectrum showed the band that corresponds to covalent bonding between silane monomers and feroxyhyte atoms. The thermal stability of polymethylmethacrylate and feroxyhyte nanocomposites is higher than that of pure PMMA, and it seems to differ from feroxyhyte content. The SEM analysis determine the size of the particle agglomerate considering the morphology of the samples. The theoretical study enabled a better understanding regarding the polymer/iron oxide interaction. The Density Functional Theory-DFT based calculations reinforces the radical trapping mechanism of nanocomposite stabilization, i.e., Fe 3+ species might be able to accept electrons from the organic phase, which decomposes via radical unzipping. The radical scavenge effect delays the weight loss of the polymer.