This paper focuses on the effects of the nano Polyhedral oligomericsilsesquioxanes (POSS) with three similar molecular structures on the thermal and electrical properties of polypropylene (PP) films, aiming to propose a comprehensive modification method. After doping with micro amount of nano POSS, the crystallinity and regularity of films are elevated. Correspondingly, PP with optimized microstructure has the lowest conductivity, due to the interaction between the nanoparticles and the matrix, as well as the strong binding force of the crystal region to the carriers. The loss of the sample is restricted, especially in the low frequency region, since the combined effect of polarization and conduction. The DC breakdown strength of the modified PP is higher than that of the PP, with an increase of above 20% at 25–85 °C. Based on quantum chemical calculations, the energy level distributions are analyzed. By selecting appropriate additives, deep trap sites can be introduced to catch carriers, preventing the breaks of polymer molecular chains. This modification of PP films shows huge potential in the improvement of dielectric properties in the field of DC capacitors.

中文翻译：

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高压直流聚合物薄膜电容器用POSS掺杂聚丙烯薄膜的介电性能改进

本文重点研究了具有三种相似分子结构的纳米多面体低聚倍半硅氧烷（POSS）对聚丙烯（PP）薄膜的热学和电学性能的影响，旨在提出一种综合改性方法。掺杂微量纳米POSS后，薄膜的结晶度和规整度得到提高。相应地，由于纳米颗粒与基体之间的相互作用以及晶区与载体的强结合力，具有优化微观结构的 PP 具有最低的电导率。由于极化和传导的综合效应，样品的损耗受到限制，特别是在低频区域。改性聚丙烯的直流击穿强度高于聚丙烯，在 25-85 °C 时提高了 20% 以上。基于量子化学计算，分析了能级分布。通过选择合适的添加剂，可以引入深陷阱位点来捕获载流子，防止聚合物分子链断裂。PP薄膜的这种改性在改善直流电容器领域的介电性能方面显示出巨大的潜力。