三明治结构多壁碳纳米管/聚醚醚酮电磁屏蔽复合材料的制备

以聚醚砜(PES)为黏结剂, 多壁碳纳米管(MWCNTs)为芯层, 聚醚醚酮(PEEK)薄膜为皮层, 制备了具有 三明治结构的MWCNTs/PEEK电磁屏蔽复合材料. 研究结果表明, 将适量的黏结剂PES引入到MWCNTs芯 层中, 当芯层层数增加到3层时, 复合材料的平均厚度仅有0.28 mm, 其密度、 拉伸强度、 5%热失重温 度(T_d,5%)、 导电率、 电磁屏蔽值及比电磁屏蔽值分别可以达到1.349 g/cm³, 80 MPa, 581.8 ℃, 2.6 S/cm, 32 dB及115 dB/mm, 是一种质量轻、 厚度薄、 机械性能好且电磁屏蔽性能高的复合材料. 其优异的综合性能主要归因于在三明治结构MWCNTs/PEEK复合材料的制备过程中, 在碳纳米管芯层中引入适量的聚醚砜作为黏结剂可以改善芯层内部碳纳米管之间及芯层与聚醚醚酮皮层之间的界面作用, 有利于芯层及芯层与皮层黏结成一个整体, 从而提高复合材料的机械性能; 同时, 芯层中碳纳米管互相搭接成密集导电网络又可以使得复合材料拥有较高的电磁屏蔽性能.

Preparation of MWCNTs/PEEK Electromagnetic Shielding Composites with Sandwich Structure

The multi-walled carbon nanotubes/polyether ether ketone electromagnetic shielding composites with sandwich-structure were prepared by using polyether sulfone（PES） as binder， multi-walled carbon nanotubes（MWCNTs） as core-layer， and polyether ether ketone（PEEK） film as surface-layer. As a result， the average thickness of PEEK/3（1PES∶4MWCNTs）/PEEK composite was only 0.28 mm when an appropriate amount of binder PES was introduced into the core-layer and the number of core-layers was increased to three. And its density， tensile strength， 5% mass loss temperature（T_d，5%）， conductivity， electromagnetic shielding value and specific electromagnetic shielding value can reach 1.349 g/cm³， 80 MPa， 581.8 ℃， 2.6 S/cm， 32 dB and 115 dB/mm， respectively， indicating that the composite has light weight， thin thickness， good mechanical properties and high electromagnetic shielding performance. These excellent comprehensive performances can be attributed to the introduction of appropriate amount of PES into the MWCNTs core-layer as binder during the preparation of composite with sandwich-structure， which can enhance the interface between the carbon nanotubes in the core-layer and between the core-layer and the surface-layer， followed by the improvement in the mechanical properties of the composite. At the same time， the dense conductive network formed by the carbon nanotubes in the core-layer can endow the composite with high electromagnetic shielding performance.