The evolution of properties of crosslinked polyethylene (XLPE)-based insulating materials under radio-chemical ageing conditions is presented and discussed. In total, seven different polymer compounds were tested, characterised by an increasing quantity of additives, for example, antioxidants (AOs) and fillers as flame retardants. Samples were analysed using different testing techniques, that is, Fourier Transform Infra-Red and dielectric spectroscopy. This allowed a broad characterisation of the polymer, bringing to good correlations between the arising of new chemical groups caused by ageing and the modifications on the complex permittivity. Phenol-based AOs are found to be the most efficient in terms of protection against oxidation. On the contrary, flame retardants are concluded not to have any impact on the material ageing. Acquired data were then treated using the principal component analysis. The data treatment successfully distinguished the material composition (with and without additives) and the ageing environments. The results confirm the relevance of this analysis in understanding the impact of irradiation on the chemical and functional properties of the polymer materials studied.

中文翻译：

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经受辐射老化的电缆绝缘层的老化评估：主成分分析在傅里叶变换红外和介电光谱中的应用

介绍并讨论了交联聚乙烯 (XLPE) 基绝缘材料在放射化学老化条件下的性能演变。总共测试了七种不同的聚合物化合物，其特点是添加剂的数量不断增加，例如抗氧化剂 (AO) 和作为阻燃剂的填料。使用不同的测试技术分析样品，即傅里叶变换红外和介电光谱。这允许对聚合物进行广泛的表征，从而在老化引起的新化学基团的出现与复介电常数的改变之间建立良好的相关性。发现基于酚的 AO 在防止氧化方面是最有效的。相反，阻燃剂被认为对材料老化没有任何影响。然后使用主成分分析处理获得的数据。数据处理成功区分了材料成分（添加和不添加添加剂）和老化环境。结果证实了该分析在了解辐照对所研究的聚合物材料的化学和功能特性的影响方面的相关性。