Abstract In this work the effect of gamma irradiation on two commercial poly(ether-urethane)s of different hard segments, namely Pellethane and Tecoflex was investigated. Electron Paramagnetic Resonance (EPR) spectroscopy was used because it is the only technique appropriate for direct detection and identification of paramagnetic intermediates in the irradiated substances. Thermal annealing was applied to compare the relative stability of the detected radicals. It was found that the dominant component of EPR spectra is a doublet which was assigned to diphenylmethyl radical in Pellethane and dihexylmethyl radical in Tecoflex, formed by the abstraction of hydrogen atom from –CH2- group located between aromatic and cyclohexane rings, respectively. The other paramagnetic product present in the wide range of temperatures is alkyl radical –CH2-CH2• localized in both segments of polyurethanes, presumably formed by scission of C–O bond. The performed studies will allow to predict radiation susceptibility of polyurethanes designed in the future.

中文翻译：

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伽马辐照聚（醚-氨基甲酸酯）的 EPR 研究

摘要 在这项工作中，研究了伽马辐射对两种不同硬链段的商用聚（醚-氨基甲酸酯），即 Pellethane 和 Tecoflex 的影响。使用电子顺磁共振 (EPR) 光谱是因为它是唯一适用于直接检测和识别受辐射物质中顺磁性中间体的技术。应用热退火来比较检测到的自由基的相对稳定性。发现 EPR 光谱的主要成分是双峰，它被指定为 Pellethane 中的二苯甲基自由基和 Tecoflex 中的二己基甲基自由基，分别由位于芳环和环己烷环之间的 -CH2- 基团中的氢原子提取形成。存在于广泛温度范围内的另一种顺磁性产物是位于聚氨酯两个链段中的烷基自由基–CH2-CH2•，可能是由 C-O 键断裂形成的。进行的研究将允许预测未来设计的聚氨酯的辐射敏感性。