The paper discusses the multi-stage analysis of thermal aging in acrylic urethane networks (AUN) and aims to establish a kinetic model for predicting the oxidation of AUN. It considers the pure thermal effects of oxidation at 160°C, 180°C, and 200°C, monitoring chemical changes using infrared spectroscopy. The study reveals that oxidation primarily induces cross-linking, leading to a decrease in rigidity (i.e., embrittlement). A new kinetic model, based on mechanisms previously established for polyamide 11, incorporates the formation of alkyl radicals through thermal decomposition, the scission of oxidized N-H bonds, and the addition of aminyl radicals.
