Electromagnetic interference (EMI) shielding materials are in great demand in electronic equipment and our surrounding environment to resist the increasing serious radiation pollution. Compared with their metal counterparts, conductive polymer composites (CPCs) have unique advantages of lightweight, corrosive resistance, low cost, and excellent processability, and are therefore an ideal choice for developing high-performance EMI shielding materials. However, CPCs based EMI shielding materials are limited to high filler loading, which caused poor mechanical properties and processability. Here, we demonstrate a facile and highly scalable approach to develop high-performance EMI shielding materials with low filler loading by using miscible poly(phenylene oxide)/polystyrene (PPO/PS) blend as the matrix. In contrast to PS/carbon nanotubes (CNTs) composites, PPO/PS/CNTs composites show much higher EMI shielding effectiveness caused by good dispersion of CNTs and highly interconnected conductive network. An excellent EMI shieling effectiveness of 23–25 dB is achieved for PPO/PS/10%CNTs composites with a thickness of only 375 µm, which is superior to most of reported polymer/CNTs composites prepared by melt-compounding. In addition, the results show that although absorption is the major shielding mechanism, the contribution of reflection is also important and closely related to the connectivity of conductive network, as well as the electrical conductivity of the CPCs.

在电子设备和我们周围环境中，对电磁干扰（EMI）屏蔽材料的需求很大，以抵抗日益严重的辐射污染。与金属同类产品相比，导电聚合物复合材料（CPC）具有重量轻，耐腐蚀，成本低和可加工性优异的独特优势，因此是开发高性能EMI屏蔽材料的理想选择。但是，基于CPCs的EMI屏蔽材料仅限于高填充量，这会导致较差的机械性能和可加工性。在这里，我们展示了一种易于使用且可扩展性强的方法，可通过使用可混溶的聚苯醚/聚苯乙烯（PPO / PS）混合物作为基质来开发具有低填充量的高性能EMI屏蔽材料。与PS /碳纳米管（CNT）复合材料相比，PPO / PS / CNTs复合材料由于CNT的良好分散性和高度互连的导电网络而显示出更高的EMI屏蔽效果。对于厚度仅为375 µm的PPO / PS / 10％CNTs复合材料，具有23-25 dB的出色的EMI抑制效果，这优于通过熔融复合制备的大多数报道的聚合物/ CNTs复合材料。此外，结果表明，尽管吸收是主要的屏蔽机制，但反射的贡献也很重要，并且与导电网络的连通性以及CPC的电导率密切相关。对于厚度仅为375 µm的PPO / PS / 10％CNTs复合材料，具有23-25 dB的出色的EMI抑制效果，这优于通过熔融复合制备的大多数报道的聚合物/ CNTs复合材料。此外，结果表明，尽管吸收是主要的屏蔽机制，但反射的贡献也很重要，并且与导电网络的连通性以及CPC的电导率密切相关。对于厚度仅为375 µm的PPO / PS / 10％CNTs复合材料，具有23-25 dB的出色的EMI抑制效果，这优于通过熔融复合制备的大多数报道的聚合物/ CNTs复合材料。此外，结果表明，尽管吸收是主要的屏蔽机制，但反射的贡献也很重要，并且与导电网络的连通性以及CPC的电导率密切相关。