利用共挤出设备,制备了导电层（石墨填充聚丙烯PPGr）和绝缘层（聚丙烯PP）叠合的层状复合物,同时制备了PPGr普通共混物。比较了层状材料与普通共混材料在结构形态、电学性能、力学性能和电磁屏蔽性能方面的差异。研究发现,普通共混物电阻率为2.04×103Ω.cm时,在低频区（500 MHz－2 GHz）和中间频段区（2 GHz－18 GHz）内的最大屏蔽值都为34dB,而层状材料电阻率为2.79×105Ω.cm时,在上述频率区间的屏蔽效果分别达到49dB和56dB。力学性能测试表明层状材料的断裂伸长率和拉伸强度也优于普通共混材料。文中提出了层状复合物中电磁波的内部多重反射机理来解释这一实验现象。
Polypropylene with a graphite filler（PPGr）/ polypropylene（PP） composites with superimposed conductive layer and insulated layer were prepared by the co-extrusion equipment,and the PPGr normal blend was also prepared.The structure and morphology,conductive properties,mechanical properties and electromagnetic interference（EMI） shielding performance of layer-structure material and normal blend were compared.It is found that the maximal shielding value of normal composites is 34 dB in both low frequency region（500MHz~2GHz） and middle frequency range（2GHz~18GHz） when its volume resistivity is 2.04×103 Ω·cm.While the corresponding shielding value for layer-structure composites are 49dB and 56dB respectively when its volume resistivity reaches up to 2.79×105 Ω·cm.The mechanical measurement indicates that the elongation at break and tensile strength of layer-structure composites are also better than that of the normal blend.The inner multiple reflection mechanism is proposed to explain the experimental phenomenon.
参考文献
| [1] | Schulz R.B.;Plantz V.C. .Shielding theory and practice[J].IEEE Transactions on Electromagnetic Compatibility,1988(3):187-201. |
| [2] | Ming-Shing Lin;Chun Hsiung Chen .Plane-wave shielding characteristics of anisotropic laminated composites[J].IEEE Transactions on Electromagnetic Compatibility,1993(1):21-27. |
| [3] | Hua Deng;Rui Zhang;Christopher T. Reynolds .A Novel Concept for Highly Oriented Carbon Nanotube Composite Tapes or Fibres with High Strength and Electrical Conductivity[J].Macromolecular materials and engineering,2009(11):749-755. |
| [4] | Deng, H;Zhang, R;Bilotti, E;Loos, J;Peijs, T .Conductive Polymer Tape Containing Highly Oriented Carbon Nanofillers[J].Journal of Applied Polymer Science,2009(2):742-751. |
| [5] | 陈旭华,易建政,殷苏东.雷达吸波材料反射系数的数值模拟[J].磁性材料及器件,2010(03):29-32,35. |
| [6] | 董晓武,李长江.炭黑（碳纤维）-聚丙烯复合型导电高分子材料的电学性能[J].高分子材料科学与工程,1992(06):89-92. |
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