镀镍石墨导电硅橡胶电磁屏蔽复合材料的制备及性能

Preparation and performance of nickelcoated graphite/silicone rubber electromagnetic shielding composites

为了改善常规方法难以兼顾电磁屏蔽橡胶高导电导磁性能和其力学性能,以镀镍石墨(NCG)为填料,偶联剂为改性剂,硅橡胶为基材,采用机械共混的方式制备了系列镀镍石墨导电硅橡胶电磁屏蔽复合材料。测试分析了电磁屏蔽橡胶的硫化特性、力学性能、导电性能和屏蔽效能,并使用扫描电子显微镜表征了电磁屏蔽橡胶的微观组织。研究了镀镍石墨(NCG)添加量对导电硅橡胶力学性能、导电性能和屏蔽效能的影响,并对电磁屏蔽橡胶的导电和屏蔽机理进行了分析。结果表明:当填料添加量为180份时,填料能够在基体内部形成完整稳定的三维导电网络,使复合材料在具有良好力学性能的同时还具有优异的电学性能,电磁屏蔽橡胶的拉伸强度为3.688MPa,体积电阻率为0.24Ω·cm,其在X波段(8.2~12.4GHz)内的平均屏蔽效能可达到55.25dB。

In order to improve the traditional methods that are difficult to balance the high conductivity,magnetic properties,and mechanical properties of electromagnetic shielding rubber(ESR),a series of nickel coated graphite(NCG)conductive silicone rubber electromagnetic shielding composite materials were prepared by mechanical blending,with coated NCG as filler,coupling agent as modifier,and silicone rubber as substrate.The vulcanization characteristics,mechanical properties,conductivity,and shielding effectiveness of ESR were tested and analyzed,and the microstructure of the rubber was characterized by SEM.The effect of NCG addition on the mechanical properties,conductivity,and shielding effectiveness of conductive silicone rubber was studied,and the conductivity and shielding mechanism of ESR were analyzed.The results show that the filler can form a complete and stable three-dimensional conductive network inside the matrix when the filler addition amount is 180 parts,so that the composite material could have good mechanical properties and excellent electrical properties at the same time,and the tensile strength of the ESR is 3.688 MPa,the volume resistivity is 0.24Ω·cm,and its average shielding efficiency in the X-band(8.2~12.4 GHz)can reach 55.25 dB.