热老化对RVV电缆绝缘层内部结构与绝缘失效机理的研究

Effect of Thermal Aging on Internal Structure of RVV Cable Insulation

利用傅里叶变换红外光谱仪对聚氯乙烯绝缘聚氯乙烯护套软电缆(RVV)绝缘层内部结构与绝缘失效机理进行研究。结果表明,未老化的电缆绝缘层不存在醇、酚、有机酸、炔烃以及烯族等化合物,其特征峰值与可能存在的官能团或化合物相关;由于标准热老化时间延长,电缆内部成分发生化学变化,红外光谱图中的特征峰值逐渐减弱;RVV电缆绝缘层热老化过程形成的CC共轭结构和O—H强极性键增强了绝缘材料的电导率,使得电缆绝缘层发生绝缘失效;热老化程度越深,电缆绝缘层越容易发生绝缘失效。

The internal structure and the mechanism of insulation failure of RVV cable insulation were studied by FFT infrared spectrometer.It showed that there were no alcohols,phenols,organic acids,alkyne,and olefin moieties in the pre-aging insulation layer.As the extension of thermal aging time,the components of cable insulation changed,C C conjugate structure and OH groups occurred,which enhanced the conductivity.The higher the thermal aging degre,the easier the insulation failure.