短切碳纤维/环氧树脂复合材料的介电性能研究

Dielectric Properties of Short Carbon Fiber Filled Epoxy Resins Composites

以短切碳纤维为填充物,环氧树脂为基体,采用涂刷法制备了碳纤维/环氧树脂基复合材料,研究了短切碳纤维的分布、含量、长度对复合材料的复介电常数的影响。碳纤维在环氧树脂基体中呈二维随机分布,随着碳纤维含量的增加,碳纤维在基体中形成导电网络的能力明显增强。采用波导法测试了复合材料在2.6～18GHz频段内的复介电常数,结果表明,在该波段,复介电常数的实部和虚部都随纤维含量的增大而增大;随纤维长度的增大先增大后减小;并随频率的增大呈现明显的频响效应。

Composites with short carbon fibers as filler and epoxy resins as matrix were prepared. CFs distri- bute randomly in epoxy resins in two-dimension（2D）. Effects caused by distribution, weight concentration and length of carbon fiber on complex permittivity of the composites were studied. The ability of forming conducting network is enhanced with the increasing short carbon fiber weight concentration. The complex permittivity and dielectric proper ties in the frequency range from 2. 6GHz to 18GHz were investigated. Both the real part and imaginary part of permi ttivity are increased with the increasing short carbon fiber weight concentration. The real and imaginary parts of per- mittivity are increased with the increasing of carbon fiber length at beginning, and then decreased with the increasing of carbon fiber length. The results show the visible frequency dependence of the real and imaginary parts of permittivi- ty with the increasing of frequency.