Thermal properties and fire propagation performance were studied for the new and aged electrical wires. Two fine electrical wires were tested using the DSC–TG and a flame spread apparatus. The main objective is to understand the thermal aging effect because the aging of electrical wire is inevitable in real service conditions. The significant discoloration occurs for PC sample during the thermal aging, while slightly changes for PN sample. The microstructure of all samples surface presents relatively smooth. The diffusion of metal from inner core to polymer insulation was discovered by the XPS. The change of these parameters including melting temperature, heat of melting, onset temperature of decomposition, mass loss, etc., is observable and complicated. The metal core also has the effect on properties of polymer insulation during the thermal aging. The difference of thermal properties between new and aged electrical wires shows that the chemical composition and structure of polymer insulation change due to thermal degradation and metal catalysis. Finally, the influence of thermal aging on the flame spread rate was also discussed. This study indicates that thermal aging coupled with the metal catalysis can promote the degradation and change the thermal or fire spread properties of polymer materials.

中文翻译：

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新的和老化的细电线的热稳定性和火焰蔓延行为的研究

研究了新的和老化的电线的热性能和火蔓延性能。使用DSC-TG和火焰蔓延设备测试了两条细电线。主要目的是了解热老化效应，因为在实际使用条件下电线的老化是不可避免的。PC样品在热老化过程中会发生明显的变色，而PN样品则略有变化。所有样品表面的微观结构都呈现相对光滑的状态。XPS发现了金属从内芯到聚合物绝缘的扩散。这些参数的变化是可观察且复杂的，包括熔融温度，熔融热，分解起始温度，质量损失等。金属芯还对热老化期间的聚合物绝缘性能产生影响。新旧电线之间热性能的差异表明，聚合物绝缘的化学成分和结构由于热降解和金属催化作用而发生变化。最后，还讨论了热老化对火焰蔓延速率的影响。这项研究表明，热老化与金属催化作用可以促进降解并改变聚合物材料的热或火势蔓延特性。