Banca de QUALIFICAÇÃO: BEATRIZ SIMÃO DE SOUZA NETA MENDES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : BEATRIZ SIMÃO DE SOUZA NETA MENDES
DATA : 01/12/2017
HORA: 08:30
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

POLYMERIZATION OPTIMIZATION OF MICROCAPSULES FILLED WITH EPOXY RESIN FOR COATINGS

PALAVRAS-CHAVES:

Microcapsules, epoxy, self-healing, mixtures diagram, interfacial polymerization

PÁGINAS: 80
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; due to the low cost and excellent chemical and mechanical properties of the epoxy polymer, the diglycidyl ether of bisphenol-A monomer (DGEBA) is used as encapsulated agent. Due to the difficulties related to the adjustment of the chemical composition of the reagents used in the synthesis of microcapsules, this work aims to optimize polymerization parameters using different formulations elaborated through mixtures diagram. Scanning electron microscopy (SEM) analysis showed that synthesized microcapsules presented a wide size distribution for all the syntheses. Best results were obtained when the epoxy monomer concentration was fixed in approximately 25% wt. and the gum arabic percentage was 7.5% wt. In these conditions, it was possible to obtain a larger quantity of microcapsules with diameter varying between 40-100 μm, making possible its application in coatings for metallic substrates. The type of emulsifier used in the syntheses had significant influence on the size and on yield of the polymerization reaction. Fourier transform infrared spectroscopy (FTIR) analyzes showed the characteristic bands of the microcapsules, attributed to their typical vibrational modes. Differential scanning calorimetry (DSC) analysis showed the characteristic thermal transitions of the encapsulated epoxy monomer and the microcapsule shell.

MEMBROS DA BANCA:
Externo ao Programa - 1064594 - EVANS PAIVA DA COSTA FERREIRA
Interno - 1202134 - JOSE DANIEL DINIZ MELO
Presidente - 1755267 - MARIA CAROLINA BURGOS COSTA DO NASCIMENTO
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE