(聚丙烯-炭黑)/聚丙烯层状复合材料的结构和电磁屏蔽性能

Structure and Electromagnetic Interference Shielding Properties of( Polypropylene-Carbon Black) /Polypropylene Microlayered Composites

利用微层共挤出设备,制备了导电层(炭黑(CB)填充聚丙烯(PP)-20%CB)和绝缘层PP叠合的层状复合物,同时制备了PPCB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,层状材料的导电性和电磁屏蔽性能均优于普通共混样,前者的体积电阻率和屏蔽峰值分别为1.96×103Ω·cm和48 dB,后者相应值分别为12.53×106Ω·cm和28 dB。力学性能测试表明,层状材料的断裂伸长率和拉伸强度(分别为654.52%,26.37 MPa)也优于普通共混材料(188.11%,24.78 MPa)。

Polypropylene with carbon black filler( PP-20% CB) / polypropylene( PP) composites with superimposed conductive layers and insulated layers were prepared by the co-extrusion equipment,and the PPCB normal blends were 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 layer-structure composites have better performance in conductivity and EMI shielding effectiveness than the normal blends. The volume conductivity and maximal shielding value of layer-structure composites are 1. 96 × 103Ω·cm and 48 dB respectively. While the corresponding values for normal blend composites are 12. 53 × 106Ω·cm and 28 dB respectively. The mechanical measurement indicates that the elongation at break and tensile strength of layer structure composites( 654. 52%,26. 37 MPa,respectively) are also better than those of the normal blend( 188. 11%,24. 78 MPa).