聚醚酰亚胺对炭黑填充环氧树脂复合材料导电性能和吸波性能的影响

利用反应诱导方法设计制备了炭黑(CB)包覆环氧树脂(EP)微球/聚醚酰亚胺(PEI)(EP/PEI/CB)复合材料。研究了该复合材料的微观结构,测量了其导电性能及在Ka波段的吸波性能,并与CB填充EP(EP/CB)复合材料进行了对比。结果表明,在EP/PEI/CB中,CB选择性分布在PEI相中并形成较规则的立体网状连续相,EP为30μm左右大小的微球分散相,与EP/CB相比具有更低的体积电阻率。EP/PEI/CB属于一种谐振腔式吸波体,在33～40 GHz范围具有较好的吸波性能且优于EP/CB,最大吸收峰出现在35.61 GHz,峰值反射率(R)为–17.40 dB,吸收带宽3.22 GHz(R–10 dB).

Influence of PEI on Conductive and Microwave Absorbing Properties of CB Filled Epoxy Resin Composites

The reaction-induced phase separation method was used to prepare carbon black(CB)coated epoxy resin(EP)microspheres /polyetherimide(PEI)(EP/PEI/CB)composites.The microstructure of the composites was investigated,and the conductivity,dielectric properties and microwave absorbing properties of the composites were characterized and compared with CB filled EP(EP/CB) composites.The results showed that the CB particles were selectively located in the PEI phase that converted to a continuous phase with a regular three-dimensional network structure,and EP presented a dispersed phase with 30 μm microspheres.Compared with EP/CB composites,EP/PEI/CB composites had lower volume electric resistance.EP/PEI/CB composites belonged to a kind of cavity resonance absorber,and had better wave-absorbing property than EP/CB composites at 33 ～40 GHz with the maximum reflection loss of –17.40 dB and absorbing band width of 3.22 GHz(below –10 dB).