微注射成型PP/MWCNTs复合材料的性能

Properties of PP/MWCNTS Composites by Micro Injection Molding

利用微注射成型制备聚丙烯/多壁碳纳米管(PP/MWCNTs)复合材料,获得特征尺寸(微试样的厚度)为100μm试样,对其微观结构、取向程度、导电性能、电磁屏蔽效能和拉伸性能进行表征和分析。结果发现,随着MWCNTs含量增加,PP/MWCNTs复合材料试样的“皮芯结构”逐渐消失,并且试样的芯层区域出现大量的取向结构。当MWCNTs质量分数由0.5%增加到5.0%时,PP/MWCNTs复合材料试样的Herman参数从0.4873增加至0.6816,电导率从3.26×10^(-5) S/cm增加至1.35×10^(-1) S/cm,拉伸强度从33.45 MPa增加至36.40 MPa,拉伸弹性模量从1023.82 MPa增加至1303.39 MPa,断裂伸长率从275.23%降低至159.33%,电磁屏蔽效能从16.02 dB增加至24.70 dB,在电磁屏蔽中吸收损耗占据主动地位。

The polypropylene/multi-walled carbon nanotubes(PP/MWCNTs)composite samples with the thickness of 100μm were obtained by micro-injection molding.The micro-structure,degree of orientation,electrical conductivity,electromagnetic shielding efficiency and tensile property of PP/MWCNTs composite samples were characterized and analyzed.The results show that that the“skin core structure”of PP/MWCNTs composite sample gradually disappears,and a large number of oriented structures appeared in the core layer region of PP/MWCNTs composite sample with the increase of MWCNTs content.As the mass fraction of MWCNTs increases from 0.5%to 5.0%,the Herman parameter of PP/MWCNTs composite sample increases from 0.4873 to 0.6816,and the conductivity increases from 3.26×10^(-5) S/cm to 1.35×10^(-1) S/cm.At the same time,the tensile strength increases from 33.45 MPa to 36.40 MPa,the tensile elastic modulus increases from 1023.82 MPa to 1303.39 MPa,the elongation at break decreases from 275.23%to 159.33%,and the electromagnetic shielding effectiveness increases from 16.02 dB to 24.70 dB.The absorption loss plays an dominant role in electromagnetic shielding.