Multilayer ternary composite polypropylene (PP) films with different content of nano-ZrO2 particles were prepared with a ternary composite PP film constructed by maleic anhydride grafted PP and nano-ZrO2 particles as the outer layer and neat PP film as the middle layer, and their physical and chemical properties as well as electrical properties were measured. The results show that the nano-ZrO2 exhibit good dispersibility in ternary composite PP system and there is a distinct interface between ternary composite PP film and neat PP film. The crystallinity of multilayer ternary composite PP films is higher than that of the single layer neat PP film. With the increase of nano-ZrO2 content, the dielectric constant of the multilayer ternary composite PP film increases, while the DC electric strength increases at first and then decreases. When the mass fraction of nano-ZrO2 reaches 1.0%, both the DC electric strength and energy storage density achieve the highest value (424.3 kV/mm and 2.14 J/cm3), which are about 10.6% and 31.3% higher than those of the single layer neat PP film. Besides, the dielectric loss factor of multilayer ternary composite PP film remains at the same level of 10-3 as that of neat PP film. The ternary composite PP and interlayer interface can jointly suppress the migration of heteropolar space charges, which contributes to improve the internal electric field distribution of dielectric, increase the electric strength, and reduce the dielectric loss caused by electron migration.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |