Effects of different environmental conditions on the mechanical characteristics of a structural epoxy

• Autor(a) principal: Silva, Patrícia Moreira
• Data de Publicação: 2016
• Outros Autores: Fernandes, Pedro Miguel Gomes, Sena-Cruz, José, Xavier, José, Castro, Fernando, Soares, Delfim, Carneiro, Vítor Hugo Pimenta
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/42058
• topic: Thermosetting resin; Chemical properties; Mechanical properties; Thermal analysis; Durability; B. Chemical properties; B. Mechanical properties; D. Thermal analysis; E. Thermosetting resin; Engenharia e Tecnologia::Engenharia Civil; Science & Technology

With the aim of characterising a commercially available epoxy adhesive used for fibre-reinforced polymers strengthening applications, when submitted to different environmental conditions, mainly thermal (TC), freeze-thaw (FT), and wet-dry (WD) cycles and immersion in pure (PW) and water with chlorides (CW) for periods of exposure that lasted up to 16 months, an experimental program was carried out. Several methodologies were used in its characterization, mainly the scanning electron microscope (SEM), dynamic mechanical analysis (DMA), standard tensile tests (STT) coupled with digital image correlation (DIC). In general the results revealed that the chemical composition was not affected by the environmental conditions. Nevertheless, it was verified through DMA and STT that the modulus of elasticity and tensile strength of the epoxy adhesive increased in the TC, while the specimens submitted to PW and CW faced a high degradation in terms of its mechanical properties. Eventually, the glass transition temperature (Tg) was not affected by the environmental conditions, apart from the specimens subjected to TC and FT, presenting a higher and lower Tg, respectively, when compared with the reference specimens.