纳米SiO_2掺杂对有水环境下间位芳纶绝缘纸性能影响的研究

为了进一步了解SiO_2纳米粒子掺杂对有水环境下间位芳纶绝缘纸性能的影响以及有、无水环境下芳纶绝缘纸性能的变化,本文利用分子动力学的方法建立了有水存在的芳纶分子模型、经SiO_2纳米掺杂后的芳纶分子模型以及无水参与的芳纶分子模型,研究了SiO_2纳米掺杂和水分对芳纶绝缘纸在玻璃转化温度、均方位移及力学模量方面的影响.研究结果表明,水分的存在使得芳纶绝缘纸的玻璃转化温度由原先的549 K降为523 K,在此基础上进行纳米SiO_2掺杂后玻璃转化温度可以由523 K提升到530 K.与无水环境芳纶绝缘纸的均方位移相对比可以发现,水分的存在在一定程度上提高了芳纶分子的链运动进而削弱了绝缘纸的热稳定性,而SiO_2纳米改性可以减弱水分对芳纶绝缘纸的这种不利影响.改性后的绝缘纸在有水环境下的力学性能得以提升,通过对比有、无水环境下芳纶绝缘纸的力学模量可以发现,一定水分的加入反而使得绝缘纸的力学性能得到了一定的提升.最后对所得模拟结果进行了理论分析,为提升芳纶绝缘纸的性能提供了有益的参考.

Study on the Influence of Nano-SiO2 Doping on the Performance of Meta-aramid Insulation Paper in Water Environment

In order to further understand the influence of SiO2 nanoparticle doping on the properties of meta-aramid insulating paper in water environment and the change of aramid insulation paper in waterless environment. In this paper, the molecular model of aramid with water, the molecular model of aramid doped with SiO2 and the molecular model of aramid with no water participation were established by molecular dynamics method.The effects of SiO2 nanodoping and moisture on the glass transition temperature, mean square displacement and mechanical modulus of aramid insulation paper were studied.The results show that the glass transition temperature of aramid insulation paper is reduced from 549K of no water participation to 523K of water environment, and the glass transition temperature in water environment can be increased from 523K to 530K after nano-SiO2 doping.Compared with the mean square displacement of aramid insulating paper in anhydrous environment, it can be found that the presence of moisture increases the chain motion of the aramid molecule to a certain extent and weakens the thermal stability of the insulating paper, while the SiO2 nano-modification can weaken this adverse effect on aramid insulation paper in water environment. The mechanical properties of the modified insulating paper in the water environment can be improved. By comparing the mechanical modulus of the aramid insulating paper in the waterless environment, it can be found that the addition of certain moisture makes the mechanical properties of the insulating paper have a certain improvement. Finally, the theoretical analysis of the obtained simulation results provides a useful reference for improving the performance of aramid insulation paper.