Aiming at the problems of large specific surface area of conventional flake boron nitride and sharp increase in resin viscosity when compounded with epoxy resin, we prepared spherical boron nitride and used it as a filler to compound with epoxy resin to prepare spherical boron nitride/epoxy composites. The preparation process and curing characteristics of spherical boron nitride/epoxy composites were studied, and the influences of the morphology and filling amount of flake/spherical boron nitride fillers on the mechanical and electrical properties of epoxy resin composites were compared. The results show that with the increase of reaction temperature, the curing degree change curve of epoxy resin shows “S” shape, and the curing process can be roughly divided into three stages of “slow-fast-slow”. In terms of mechanical properties, adding a small amount of boron nitride can improve the mechanical properties of the epoxy resin composites; when the filling amount is high, spherical boron nitride/epoxy composites have better mechanical properties than flake boron nitride/epoxy composites. In terms of electrical properties, the relative dielectric constant of the epoxy resin composites increases with the increase of boron nitride content, and the dielectric loss factor is lower than 0.02; compared with the flake boron nitride/epoxy composites, the spherical boron nitride/epoxy composites have less “filler-resin” interface, lower relative dielectric constant and dielectric loss factor; adding an appropriate amount of boron nitride can significantly improve the volume resistivity and electric strength of composites.
| 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 |