The growing demand of polymer-metal hybrids as structural components in the automotive, aerospace, medical and military applications may require long-term stability under thermal stresses. A full understanding of the long-term performance of bonded structures subjected to high temperature is required to use these products in engineering and industrial applications. In real applications, temperature will be higher at the proximity to the steel substrate, therefore, the boundary between steel and polymer suffers the highest thermal stress and, therefore, a collapse of the structure starting at this boundary is most likely. In this work, kinetic parameters of thermal decomposition of a thermoplastic polyurethane, TPU, were evaluated through the Flynn-Wall, Friedman and Chang methods. Tests were conducted at three different heating rates, 5, 10 and 15 K/min and different kinetic parameters were obtained, such as the activation energy, reaction order and the pre-exponential factor. These parameters were useful to predict the lifetime of the polymer that was in direct contact with the metal substrate, assuming a continuous operation work at certain temperatures.