Banca de DEFESA: BEATRIZ SIMÃO DE SOUZA NETA MENDES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : BEATRIZ SIMÃO DE SOUZA NETA MENDES
DATA : 08/03/2018
HORA: 08:30
LOCAL: A definir
TÍTULO:

Synthesis of microcapsules filled with epoxy for application in self-healing systems.

PALAVRAS-CHAVES:

Microcapsules, epoxy, self-healing, mixture diagram, interfacial polymerization.

PÁGINAS: 96
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Polímeros, Aplicações
RESUMO:

Engineering design involving self-healing materials have been increasingly developed through the use of different strategies, such as microencapsulation, molecular interdiffusion in thermoplastic polymers, photoinduced self-healing, recombination of polymer chain ends, among others. This work focuses on the microencapsulation strategy through interfacial polymerization; where the diglycidyl ether of bisphenol A monomer (DGEBA) was used as encapsulated agent. From the mixtures diagram the proportions of reagents to be used in the synthesis with the objective of obtaining microcapsules with satisfactory characteristics for application in self-healing systems were studied. The influence of gum arabic emulsifiers and Tween 80 and their concentrations on the particle diameter were analyzed. The use of gum arabic as an emulsifier gave rise to microcapsules with a mean diameter of 73 μm, however, the stabilization of the emulsion was not adequate, leading to a reduction in reaction yield. On the other hand, when Tween 80 was used, microcapsules with a mean diameter of 19 μm were obtained, however, a greater stabilization of the emulsion resulted in a higher yield of the polymerization reactions. Fourier transform infrared spectroscopy (FTIR) analyzes showed the characteristic vibrations of the microcapsule material. Differential scanning calorimetry (DSC) analysis showed the characteristic thermal transitions of the encapsulated epoxy monomer and microcapsule shell. The self-healing effect was verified for microcapsules synthesized with the two types of emulsifier separately, and it was possible to observe that, despite the smaller diameter of the microcapsules synthesized with Tween 80, satisfactory results were obtained for the coating containing these microcapsules.

MEMBROS DA BANCA:
Externo à Instituição - AMELIA SEVERINO FERREIRA E SANTOS - UFPB
Externo ao Programa - 1064594 - EVANS PAIVA DA COSTA FERREIRA
Interno - 1202134 - JOSE DANIEL DINIZ MELO
Externo à Instituição - JOSIANE DANTAS VIANA BARBOSA - Senai
Presidente - 1755267 - MARIA CAROLINA BURGOS COSTA DO NASCIMENTO
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE