热老化条件下LDPE/TiO2纳米复合材料介电特性研究

Dielectric properties of LDPE/TiO2 nanocomposites under heat aging

电力电缆在运行过程中普遍存在的热老化现象容易加速绝缘失效,限制设备使用寿命,甚至引发电力系统故障。纳米粒子掺杂改性可以提高聚乙烯基体材料的热稳定性,开展相关研究可以为提高电缆绝缘寿命提供解决方案。以低密度聚乙烯(LDPE)/二氧化钛(TiO2)纳米复合材料为研究对象,分别研究了热老化条件下纳米粒子质量分数、老化时间、老化温度对材料介电特性的影响。实验结果表明,掺杂TiO2纳米粒子能够改善LDPE基体材料的介电特性,当TiO2纳米粒子填充质量分数为0.5%时,纳米复合材料介电特性最佳。老化时间和老化温度是影响材料介电特性劣化的两个重要因素,随着老化时间推移和老化温度提高,纳米复合材料的介电性能劣化现象越明显。对聚乙烯材料进行纳米改性的同时降低电缆运行环境温度,对提高电缆绝缘寿命具有重要意义。

The thermal aging phenomenon that is common in power cables during operation is likely to accelerate insulation failure,limit the service life of equipment,and even cause power system failure.Nanoparticle doping modification can improve the thermal stability of polyethylene matrix materials,and related research can provide solutions for improving cable insulation life.LDPE/TiO2 nanocomposites are studied,and the effects of nanoparticle concentration,aging time and aging temperature on the dielectric properties of the materials are studied under heat aging conditions.The experimental results show that the doping of TiO2 nanoparticles can improve the dielectric properties of LDPE matrix materials.When the filling fraction of TiO2 nanoparticles is 0.5%,the dielectric properties of nanocomposites are the best.The aging time and aging temperature affect the dielectric properties of materials.Two important factors of characteristic deterioration,as the aging time increases and the aging temperature increases,the dielectric properties of nanocomposites deteriorate more.Nano-modification of polyethylene materials while reducing the operating temperature of the cable is of great significance for improving cable insulation life.