逾渗复合体系的结晶度对逾渗阈值和介电行为的影响

Effect of the Matrix Crystallinity on the Percolation Threshold and Dielectric Behavior in Percolative Composites

通过制备不同结晶度的聚乙烯(PE)基体,研究基体结晶度对逾渗复合体系的逾渗阈值和介电行为的影响。结果显示逾渗阈值与基体的结晶度呈反比关系,而介电常数的增加与基体结晶度呈正比。提出用二维图表反映这种关系。此外,还发现绝缘体-导体的转变在以低结晶度为基体的复合材料中更易出现,这可能对制备具有高介电常数、低损耗的逾渗复合材料有利。

Through the use of polyethylenes with different erystallinities as matrices, the effects of the matrix crystallinity on the percolation threshold and dielectric behavior of percolative composites have been investigated. The results suggest that the percolation threshold is negatively related to the matrix crystallinity, whereas the enhancement of the dielectric constant is positively related to the matrix crystallinity. A two-dimensional diagram is proposed to illustrate such relationships. In addition, it has been found that the insulator-conductor transition is much flatter in low - erystallinity - matrix -based composites, and this may be favorable for preparing threshold composites with a high dielectric constant and a low loss tangent.