Zhao Liang, Yu Binxiong, Shang Wei
Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024, China.
College of Advanced Multidisciplinary Studies, National University of Defense Technology, Changsha 410073, China.
Polymers (Basel). 2022 Apr 20;14(9):1653. doi: 10.3390/polym14091653.
The layer number effect on electric breakdown strength () of multi-layer polymer films is investigated using 10-μm polypropylene (PP) films under a dc condition. The layer number, , of the films during the test is as large as 120. It is observed that the relation between and conforms to a minus power law, i.e., () = , where the power exponent, , is 0.27, is a constant. By reviewing the experimental data in references, it is found that the power law holds true for different types of polymers in different test conditions, but the value of varies from 0.072 to 0.5. The variation of is explained in perspective of the discontinuous structures within films and those between films. A small value of means a good purity level of the film, which is due to the decrease of the size of the inter-layer defects. A large value of means a poor purity level of the films, which is due to the increase of the amount of intra-layer defects. Both factors influence the value of , leading to the variation of .
在直流条件下，使用10μm的聚丙烯（PP）薄膜研究了层数对多层聚合物薄膜电击穿强度（）的影响。测试过程中薄膜的层数高达120层。观察到与之间的关系符合负幂律，即（）=，其中幂指数为0.27，为常数。通过回顾参考文献中的实验数据，发现幂律在不同测试条件下对不同类型的聚合物均成立，但的值在0.072至0.5之间变化。从薄膜内部和薄膜之间的不连续结构角度解释了的变化。较小的值意味着薄膜的纯度水平较高，这是由于层间缺陷尺寸的减小。较大的值意味着薄膜的纯度水平较低，这是由于层内缺陷数量的增加。这两个因素都会影响的值，导致的变化。
