This study addresses the multiscale analysis of acrylic urethane networks (AUN). To establish the kinetic model for predicting AUN oxidation, this study considered the pure thermal oxidation of AUN at 160, 180, and 200 °C. Chemical changes were monitored using infrared spectroscopy. These indicated the presence of an imide, presumably generated from the oxidation of CH₂ at the α-position of nitrogen. On the macromolecular and macroscopic scales, oxidation was shown to induce predominant crosslinking, leading to a drop in toughness (i.e., embrittlement). The novel kinetic model of AUN thermal aging was developed from a mechanistic scheme previously established for polyamide 11, by adding some extra paths of thermolytic alkyl radical formation, oxidative NH bonds decomposition and coupling of aminyl radicals.

这项研究解决了丙烯酸聚氨酯网络 (AUN) 的多尺度分析。为了建立预测 AUN 氧化的动力学模型，本研究考虑了 AUN 在 160、180 和 200 °C 下的纯热氧化。使用红外光谱监测化学变化。这些表明存在酰亚胺，推测是由氮的α-位处的CH ₂氧化产生的。在大分子和宏观尺度上，氧化显示出主要的交联，导致韧性下降（即脆化）。AUN 热老化的新动力学模型是从先前为聚酰胺 11 建立的机制方案开发的，通过添加一些额外的热解烷基自由基形成路径、氧化 NH键分解和氨基自由基的偶联。