Akademik Veri Yönetim Sistemi
Journal of Structural Engineering & Applied Mechanics (Online), cilt.7, sa.1, ss.24-33, 2024 (Hakemli Dergi)
Creep behavior is observed even at room temperature in polymers and polymer
composites under constant stress. In the design of structural elements using these
materials, the determination of creep compliance for structural strength and
performance analysis is crucial in terms of reliability and usability. In this study, the
creep compliance of pure epoxy and functionalized graphene-reinforced epoxy
nanocomposites were experimentally investigated and compared at room
temperature at constant stress levels of 50, 100, and 200 MPa representing the
viscoelastic region, yielding region and viscoplastic region, respectively. To reveal
the effect of temperature as well as stress level on this behavior, the creep
compliance of epoxy and graphene-epoxy nanocomposites was investigated at 65°C
in addition to room temperature after the pure graphene used as a reinforcement
element was functionalized with Triton X-100, nanocomposite production was
carried out. In 2h creep tests, it was observed that as the constant stress level
increased, the creep compliance increased and the creep compliance of the
nanocomposite was lower than that of the epoxy at all stress levels. The creep
compliance of the epoxy was improved by 65% with the addition of functionalized
graphene at room temperature and a stress level of 100 MPa. As the temperature
increased, the creep compliance of both epoxy and functionalized graphene-epoxy
nanocomposite increased due to molecular mobility and viscous flow. However, at
high temperatures, the positive effect of functionalized graphene on the compliance
of the epoxy is higher. At 65°C and a stress level of 100 MPa, the improvement rate
of creep compliance is 78%. Functionalized graphene exhibited a more effective
behavior on creep resistance at high temperatures. The obtained results showed that
creep compliance was significantly affected by stress level and temperature.