Banca de DEFESA: MATHEUS MENDES DE OLIVEIRA
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : MATHEUS MENDES DE OLIVEIRA
DATA : 10/12/2020
HORA: 14:00
LOCAL: Remota
TÍTULO:
Influence of processing on electrical and mechanical properties of epoxy nanocomposites filled with carbon nanoparticles
PÁGINAS: 80
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Polímeros, Aplicações
RESUMO:
Advances in mechanical properties of composites over the past decades have enabled the aerospace industry to shift their fuselage design from aluminum to fiber-reinforced polymers. However, their insulating character renders the airplane structure vulnerable to serious damage when hit by lightning strikes, including embrittlement and delamination. The current solution has been the use of a metallic wire mesh bonded to the fuselage, but it adds extra weight, undermining the very advantage of using composites. Therefore, the industry would benefit from a lighter and seamless solution. Graphene nanoplatelets (GNP) and carbon nanotubes (CNT) have been used to enhance mechanical and electrical properties of epoxy-based nanocomposites. GNPs are small stacks of multilayer graphene that inherit some of the excellent mechanical and electrical properties of its single layered counterpart, but at a much lower manufacturing cost. CNTs are well known for their high conductivity and low percolation threshold, as well as high Young’s modulus. There is evidence in the literature that mixing both nanoparticles gives rise to synergetic effects, but there is still no consensus on many key factors in the design of these hybrid nanocomposites, especially those concerning optimized processing and ideal weight fraction. The first part of this work aimed at using rheological measurements to shed some light on how sonication parameters affect dispersion state in uncured GNP-CNT-epoxy hybrid nanocomposites, and then evaluate their impact on electrical and mechanical properties of cured samples. Results revealed that time and amplitude have great impact on these properties and confirm that careful control of sonication parameters are crucial in optimizing the fabrication of advanced hybrid nanocomposites. The second part of the work focused on investigating the alleged synergetic effect of CNT-GNP-epoxy hybrids. Different CNT:GNP ratios were tested at 0.1 and 1.0 wt. %. While the lower concentrated hybrids did not show clear synergy, at 1.0 wt.% the 7:3 and 9:1 ratios achieved higher electrical conductivity and the 1:9 and 3:7 ratios improved E’ and Tg when compared to mono-filled samples. The possible causes of the synergetic effect are discussed.
MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Titular - Examinador(a) Externo à Instituição - GUILHERMINO JOSÉ MACÊDO FECHINE - UPM
Membro Titular - Examinador(a) Externo à Instituição - GLAURA GOULART SILVA - UFMG
Membro Suplente - Examinador(a) Interno ao Programa - 1763443 - MARCIA APARECIDA DA SILVA SPINACE
Membro Suplente - Examinador(a) Externo ao Programa - 1730526 - SUEL ERIC VIDOTTI