An Approach to Predict Thermal Degradation Characteristics of Ethylene Propylene Diene Monomer and Rocasin Elastomers Under Extreme Heating Rate for High‐Temperature Insulation Application

The thermal degradation behavior of EPDM and Rocasin elastomers at heating rates far exceeding the capability of conventional thermogravimetric analysis (TGA; limited to approximately 200°C/min) remains poorly characterized, despite the critical role of these materials in rocket motor insulation, cable sheathing, and high‐temperature sealing applications. This study addresses that gap by deriving thermal degradation kinetics from TGA experiments at β = 10–150°C/min under a nitrogen atmosphere and extending the validated models to simulate degradation behavior at extreme heating rates of 500–2000°C/min, mainly for rocket motor applications. In this study, EPDM and Rocasin elastomers are heated to 1000°C at different heating rates from 10 to 150°C/min. The degradation mechanisms across various temperature ranges were studied along with the kinetic models to elucidate the kinetic parameters. The degradation pattern of the materials was simulated and compared with the data within the limits of TGA. Furthermore, these parameters were used to construct a preliminary kinetic‐extrapolation framework for predicting degradation behavior beyond the limits of conventional TGA, which may serve as input for subsequent coupled transient heat transfer and ablation modeling of insulation systems.