The effect of gelcoats on hydrothermal and ultraviolet light induced aging of polymer composites

Fiber reinforced polymer composite materials are increasingly being used in outdoor environments where they are exposed to environmental conditions. In particular, questions concerning the durability of polymer-based composite materials exposed to temperature, humidity and ultraviolet (UV) radiation have been raised. In this thesis, the effects of fiber type and stacking sequence of the glass fiber and carbon fiber reinforced epoxy composite materials, the value of temperature in the environment of hydrothermal and ultraviolet radiation and gelcoat coating and the color of this gelcoat on the aging of the material were experimentally investigated. As a result of the tests, it has been observed that carbon fiber material is more resistant to environmental conditions than glass fiber material. In addition, the ambient temperature and the ultraviolet light have a significant effect on the aging of the material and in the materials coated with gelcoat, the properties of the material such as mechanical, glass transition temperature, low velocity impact perforation threshold was less affected by the same environmental conditions than the uncoated material. However, gelcoat color has been observed to have a significant effect on the aging of the material. The variation of various properties of the composite materials with aging environment and duration were determined with tensile, dynamic mechanical analysis, low-velocity impact, three-point bending, interlaminar shear tests. These variations are presented in tables and graphs.