Modeling of oxidative development in PMR-15 resin

A multidisciplinary approach focused on models and processes to predict the performance and life expectancy of high-temperature polymer matrix composite (HTPMC) materials used in a variety of aerospace applications is being developed. Emphasis is on the implementation and extension of hierarchical models to represent the polymer behavior/properties as a function of the degradation state. Neat resin specimens of high-temperature polyimide PMR-15 have been evaluated for various aging conditions. Characterization of the properties of the polyimide is focused on development of a constitutive law for use in a micromechanical analysis to predict the behavior of PMR-15 reinforced composites. Thermo-oxidative aging is simulated with a diffusion-reaction model in which temperature, oxygen concentration and weight loss effects are considered. One-dimensional simulations illustrate oxidative layer growth for neat resin specimens. Comparisons and correlations with experimental observations of oxidation layer growth are presented.