Date of Graduation
Statler College of Engineering and Mineral Resources
Chemical and Biomedical Engineering
Eung H. Cho.
This study investigated the aging of urethane modified vinyl ester (UMVE) and urethane GFRP (glass fiber reinforced polymer) when exposed to alkaline solution. Samples from both composites were exposed to alkaline solution with sustained load for six months. The sustained load on each sample was approximately 34.5 MPa or 16--20 percent of their tensile strength. The second experiment exposed both types of GFRP to alkaline solution without load for six months. The final experiment determined the alkaline solution diffusion coefficients through each GFRP polymer by measuring the change in mass of each sample as a function of time.;After the GFRP samples were aged for six months, their tensile strengths were measured and compared with the tensile strength of non-aged samples to measure the aging effect. It was found that alkaline solution alone (without sustained load) did not significantly reduce or change the tensile strength of any of the samples. However, the presence of sustained load greatly increased the aging effect. UMVE GFRP experienced a tensile strength reduction of 27.3 percent while urethane GFRP lost 57.5 percent of its original tensile strength. In all cases, the maximum alkaline solution uptake for urethane GFRP samples was more than double the uptake of UMVE GFRP samples. The more severe aging effect seen in urethane GFRP samples may be directly related to the increased alkaline solution uptake observed for the urethane based samples.
Mounts, Joshua L., "Durability of glass-fiber-reinforced polymer composites in an alkaline environment" (2007). Graduate Theses, Dissertations, and Problem Reports. 1804.