High Temperature Chemical Degradation of PMR-15 Polymer Resins

PMR-15 is a polymer resin for glass and carbon reinforced composites used for high temperature, civilian and military aerospace applications. The harsh environments of PMR-15 applications lead to long term structural degradation and, in turn, impact the readiness capabilities of the system. This study investigated the thermal and oxidative degradation of PMR-15 neat resin powder through the use of thermal gravimetric analysis (TGA) in oxygen, argon and air at isothermal hold temperatures of 260, 288, 316, and 343 -C for 250 hours. The TGA measured the degradation by recording the change in neat resin powder mass versus time. The qualitative results were similar for all tests. The specimens initially lost weight at a rapid rate followed by a reduction in the weight loss rate to a near constant value that was dependent upon the isothermal temperature and the gaseous environment. The data from these tests will be used by researchers in the Air Force Research Laboratory Materials and Manufacturing Directorate to further efforts made towards developing a constitutive law and the associated models to predict the behavior of polymer matrix reinforced composites.