【摘要】 描述了一种利用多元复合导电网络提高有机硅橡胶复合材料导电和电磁屏蔽性能的思想。这种含有多元复合导电网络的复合材料是通过将镀银泡沫、导电填料和有机硅橡胶复合在一起而制备的。利用扫描电子显微镜观察了复合材料的微观结构,采用电阻测试仪、矢量网络分析仪、热失重分析仪分别研究了复合材料的导电性、电磁屏蔽性能及热稳定性,并探讨了补强剂SiO2对这些性能的影响。结果表明,2%碳纳米管/导电泡沫/硅橡胶多元复合体系相比于2%碳纳米管/硅橡胶单一复合体系电阻率降低了6个数量级,平均电磁屏蔽效能由12dB提高到52dB,增大了4倍。当导电填料换为炭黑后,2%炭黑/导电泡沫/硅橡胶多元复合体系相比于2%炭黑/硅橡胶单一复合体系电阻率降低了7个数量级,平均电磁屏蔽效能由10dB提高到50dB,增大了5倍。由于多元复合导电网络,材料的导电性能和电磁屏蔽性能大幅度提升。此外,补强剂的加入增大了复合材料的热稳定性,但降低了其导电和电磁屏蔽性能。更多还原

【Abstract】 In this article,an idea of using multiple conductive networks to improve the conductivity and electromagnetic shielding effectiveness(EMI SE)of the organic silicon rubber composite is described.The composite with multiple conductive networks was fabricated by combining electroless silver plating foam and low conductive fillers with the organic silicon rubber.Scan electron microscope is applied to observing the microstructure of the composites.Resistance tester,vector network analyzer,and thermo-gravimetric analyzer are respectively used for the characterization of the conductivity,EMI SE,and thermal stability of the composite.The effect of the fortifier nano SiO2 on these properties is also discussed.The results show that the resistivity of the multiple composite system 2wt% carbon nanotubes(CNTs)/conductive foam(F)/silicone rubber(SR)decreases 6orders of magnitude compared to the one-part composite system 2wt% CNTs/SR.The average EMI SE,which has increased from 12 dB to 52 dB,is 4times than that of the system 2wt% CNTs/SR.When the filler replaces with carbon black(CB),the resistivity of the multiple composite system 2wt% CB/F/SR is 7orders of magnitude lower than that of the one-part composite system 2% CB/SR.The average EMI SE,which has increased from10 dB to 50 dB,is 5times higher than that of the system 2% CB/SR.The conductivity and the EMI SE are significantly enhanced due to the multiple conductive networks.In addition,the thermal stability of each composite system is improved at the presence of the fortifier,but the conductivity and EMI SE has decreased.更多还原