还原石墨烯复合材料的力学和电磁性能

采用水合肼对氧化石墨烯进行还原,获得2种含氧量不同的还原石墨烯(rGO),与双马来酰亚胺(BMI)树脂溶液混合并通过湿法预浸工艺制备碳纤维(CF)预浸料,采用热压成型工艺制备rGO-CF/BMI复合材料单向板。研究了rGO的还原程度及含量对复合材料力学性能、玻璃化转变温度及电磁性能的影响。结果表明:在较高温度下制得的rGO_2比在较低温度下制得的rGO1具有更高的还原程度,rGO_2在树脂中的分散性相对较差。当rGO1与rGO_2的质量分数分别为0.1%和0.05%时,rGO1-CF/BMI复合材料和rGO_2-CF/BMI复合材料的层间剪切强度分别达到最高,相对于CF/BMI复合材料均提高约14%,而弯曲性能和玻璃化转变温度基本不变。rGO_2-CF/BMI复合材料的介电性能优于rGO1-CF/BMI复合材料,当rGO_2的质量分数为0.1%时,在12.4~18.0GHz的频率范围内,rGO_2-CF/BMI复合材料的介电常数实部较CF/BMI复合材料最高提高约6倍,介电损耗最高提高约3倍。在该频率范围内,rGO1-CF/BMI和rGO_2-CF/BMI复合材料均呈弱磁性,对入射电磁波的作用为高反射、低吸收。

Mechanical and electromagnetic properties of reduced graphene composites

The graphene oxide was reduced by hydrazine hydrate to attain two kinds of reduced graphene oxide (rGO) with different oxygen contents. The prepreg was prepared from carbon fiber (CF) and bismaleimide (BMI) resin by wet impregnating process, then the rGO-CF/BMI composite unidirectional laminates were manufactured by hot pressing process. The relationship between reduced degree and content of rGO and mechanical properties, glass transition temperature and electromagnetic properties of composites was studied. The results show that the reduced degree of rGO2 which was attained under the higher temperature is larger than that of rGO1 which was attained under the lower temperature, the dispersion of rGO2 is poorer than rGO1 in resin. The interlaminar shear strength of rGO1-CF/BMI and rGO2-CF/BMI composites will both be enhanced about 14% compared to CF/BMI composites when the mass fraction of rGO1 and rGO2 is 0.1% and 0.05% respectively, however, the flexural properties and glass transition temperature are basically unchanged. The dielectric properties of rGO2-CF/BMI composites are superior to those of rGO1-CF/BMI composites. When the mass fraction of rGO2 is 0.1%, the real part dielectric constants of rGO2-CF/BMI composites will increase by over 6 times than those of CF/BMI composites, as well as the dielectric losses will increase by over 3 times at the frequency range of 12.4-18.0 GHz. Moreover, the magnetic properties of rGO1-CF/BMI and rGO2-CF/BMI composites are pretty weak, thus the interaction between the composites and electromagnetic wave is mainly reflection, rather than absorption.