Ref.: MCoFsu04-002
Apresentador: graziele lopes de souza
Autores (Instituição): souza, g.l.(Universidade Federal do Rio Grande do Norte); Nascimento, R.M.(Federal University of Rio Grande do Norte); Paskocimas, C.A.(Univ. Federal Rio Grande do Norte); Cysne Barbosa, A.P.(Universidade Federal do Rio Grande do Norte);
Resumo:
A composite is defined as the combination of two chemically distinct materials with an interface separating them. They are used to obtain specific properties, different from those found in each constituent alone. And to ensure these properties, the interfaces must be chemically bonded.
The glass fibers are widely used in polymer reinforced composites due to their competitive qualities. Glass/Epoxy composites are the most used systems to support impact loads, as mentioned by Otogo Be. and his team in 2023. A composite with fiber/matrix interfaces with cohesive strong bonds usually has high stiffness and high mechanical strength. However, strong bonds can reduce the toughness and fatigue resistance of the latter. Soft bonds generally improve dynamic properties by promoting energy dissipation through the interfacial area as mentioned in the work by N. Ranganathan in 2016 and M. Bar in 2020.
These properties can be achieved from a surface treatment of the fiber impacting the interfacial properties and, as a result, the durability of the composite from a mechanical and environmental point of view. A properly coupling agent that forms stable chemical bonds between the matrix and the reinforcement can thus limit the diffusion of water at the interface and consequently the impact on mechanical properties. Characterizing the interphase regions is difficult due to their dimensions and the various interactions between their components, however there are several studies showing the potential of dynamic mechanical analysis (DMA).
An important condition of these reinforced is that they can be affected by storage. After storage, before use, they may have modifications with a significant impact on the final performance of the composite.
Not all available sizes and shapes of these fibers have the same storage stability, which is also influenced by the purchase packaging. The objective of this work was to characterize glass fibers that will be used for epoxy matrix composites. Focusing on the effect of the storage time of the fiber roll under different temperature and humidity conditions and how this may have affected the surface of these to modify the chemical bonds of the interface. Characterization tests were carried out on the surface of the glass fibers, as well as on some composite samples to evaluate the matrix/fiber adhesion