Effect of water on the mechanical properties of fiber reinforced polymers

As part of an ongoing product design effort, the effects of exposure to water on the mechanical performance of several thermoset polymer materials are evaluated. A series of tests were performed on a suite of thermoset materials, some with, and some without, fiber reinforcement. Aging of the materials in water is performed at elevated temperatures to accelerate any damage mechanisms. As control conditions, some samples are aged in air at the same temperatures, sealed to prevent wicking of liquid through the fibers, placed through the curing process for the epoxy sealant, and conditioned at elevated temperature air for one week prior to exposure to elevated temperature water. Trends observed from several materials are compared. Factors that are evaluated include the presence of fiber-reinforcement, a process of coating edges of samples to avoid wicking of liquid into the material, and the rate at which environmental effects occur. In addition, general conclusions are drawn regarding the development of test matrices to evaluate suitability of polymer-based materials for conditions that include exposure to water.