Banca de QUALIFICAÇÃO: ÉRICK STÉFANO SILVEIRA GUERRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ÉRICK STÉFANO SILVEIRA GUERRA
DATA : 02/09/2019
HORA: 08:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

SELF-HEALING IN EPOXY MATRIX COMPOSITES AND CORRELATION WITH INTERFACE PROPERTIES

PALAVRAS-CHAVES:

Self-healing, composite materials, thermo-mechanical properties, micromechanical tests.

PÁGINAS: 60
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Polímeros, Aplicações
RESUMO:

Fiber reinforced polymers (PRF) have been increasingly considered for structural applications due to their properties. The formation of microcracks in the polymer matrix is of concern as it can lead to failure, especially in structures subjected to repeated loading. However, due to the difficulty in detecting these microcracks and accessing certain regions of a component, traditional detection and repair techniques may be ineffective. Thus, PRFs with self-healing capability are of great interest. In one of the self-healing approaches, a thermoplastic is incorporated into the thermoset matrix and healing is achieved when heating allows the thermoplastic to gain mobility, flow and fill into microcracks, repairing the fracture surface and restoring - partially or fully - the mechanical properties of the material. Poly(ethylene-co-methacrylic acid) (EMAA) has been the most studied thermoplastic repair agent due to its adequate physical and mechanical properties for self-healing purposes.  In this work, the effect of adding EMAA to glass fiber reinforced epoxy matrix composites will be studied. The repair efficiency of EMAA will be evaluated and correlated with adhesion studies among thermoplastic, fiber and matrix through measurements of interfacial properties. The effect of the content of EMAA added was investigated using Dynamic-Mechanical Analysis (DMA) and Fourier Transform InfraRed Spectroscopy (FTIR). The adhesion properties will be studied by single-lap shear tests. DMA results showed that EMAA additions greater than 5 wt.% increase the glass transition temperature (Tg) of the samples, indicating that reactive EMAA may affect epoxy network formation. FTIR spectroscopy analysis showed that the thermoplastic EMAA reacted with the epoxy resin, suggesting that the repair agent affected the formation of the thermosetting network. Adhesion tests are being conducted. Macromechanical tests using tapered double-cantilever beam (TDCB) will be performed to evaluate repair efficiency, while single fiber micromechanical tests will be conducted to investigate the effect of the addition of EMAA on fiber-matrix, matrix-particle and particle-fiber interfacial properties. Finally, a new methodology for evaluating repair efficiency using micromechanical tests will be developed and evaluated.

MEMBROS DA BANCA:
Externo à Instituição - PEDRO DOLABELLA PORTELLA - BAM
Interna - 2042234 - ANA PAULA CYSNE BARBOSA
Externo ao Programa - 1064594 - EVANS PAIVA DA COSTA FERREIRA
Presidente - 1202134 - JOSE DANIEL DINIZ MELO