Banca de DEFESA: MIRELLA LOPES DA ROCHA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MIRELLA LOPES DA ROCHA
DATE: 10/09/2021
TIME: 14:00
LOCAL: Sala virtual: https://meet.google.com/xcx-zavm-xma
TITLE:

Accelerated aging effects of composites employed as repair materials for steel pipelines in the oil industry

KEY WORDS:

Composites, glass fiber, epoxy resin, Pipelines, repair, accelerated aging.

PAGES: 131
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Materiais Conjugados Não-Metálicos
SUMMARY:

Pipelines are structures used in large scale in the oil industry for transportation of fluids which are, in turn, highly corrosive to the duct, leading to damages over time. Moreover, besides corrosion itself, failures can occur during the manufacturing or installation of these ducts. Considering these defects, the degradation of the pipelines and the high cost of their implementation, repairs with composite material reinforced with glass fiber becomes a viable alternative, considering its high chemical resistance and its excellent thermal and mechanical performances. However, studies on the effects of aging on these repairs are still necessary for greater reliability on their usage at oil industry. Therefore, the objectives of this study are to evaluate the effects of accelerated aging on the composite used at pipelines repair by exposing them to accelerated aging in two types of environment: salt water and UV exposure with water condensation, for two, four and six months. The tests conducted to evaluate the material where: mass variation, scanning electron microscopy (SEM), dynamic-mechanical analysis (DMA), Fourier-transform infrared spectroscopy (FTIR), permeability test and lap shear. The results showed that samples submitted to aging in salt water presented mass gain, while the ones aged at UV and humidity exposure presented mass loss. FTIR spectroscopy showed chemical modifications in all studied aging conditions. SEM showed changes in the aged materials such as cracks, fiber-matrix detachment and exposure of fibers. DMA showed an increase in the glass transition temperature for aged materials when compared to the unaged one. Permeability tests showed an increase at gas permeability for aged samples when compared to the unaged material. Finally, lap shear tests showed a reduction in shear strength of aged materials, for all aging conditions.

BANKING MEMBERS:
Interna - 2042234 - ANA PAULA CYSNE BARBOSA
Interno - 1202134 - JOSE DANIEL DINIZ MELO
Externo ao Programa - 1064594 - EVANS PAIVA DA COSTA FERREIRA
Externa à Instituição - LAURA HECKER DE CARVALHO - UFCG
Externa à Instituição - MIRABEL CERQUEIRA REZENDE - ITA