Injection Molded Segregated Carbon Nanotube/Polypropylene Composite for Efficient Electromagnetic Interference Shielding

Constructing segregated structure in conductive polymer composite (CPC) is effective to achieve high electromagnetic interference shielding effectiveness (EMI SE) at low filler loading. Nevertheless, the present segregated CPCs were only fabricated via the compression molding technique, which limits their practical application. In this work, the injection molding technique was utilized for the first time to develop a carbon nanotube (CNT)/isotactic polypropylene (iPP)/atactic polypropylene (aPP) composite with typical segregated structure. The injection molded segregated CNT/PP composite exhibits an excellent EMI SE of 43.1 dB, which is 67% higher than the CNT/PP composite with randomly distributed CNTs, at the same CNT loading of 5.0 wt %. Such EMI SE is also comparable to the value for segregated CNT/PP composites prepared by compression molding. Our work provides a promising strategy to develop segregated CPCs via an efficient injection molding technique, in comparison to the compression molding technique.