Improved mechanical and electromagnetic interference shielding performance of segregated UHMWPE/CNTs via microwave-assisted sintering

Abstract

Constructing the segregated networks is an efficient strategy to simultaneously achieve the high electrical conductivity and electromagnetic interference (EMI) shielding performance in conductive polymer composites (CPCs). Herein, an advanced molding technique based on microwave (MW)-assisted sintering was proposed to prepare the segregated ultrahigh molecular weight polyethylene/carbon nanotube (UHMWPE/CNT) composites. Scanning electron microscopy and optical microscopy images indicated that CNTs enriched on the surfaces of UHMWPE granules through ball milling, and the clear and complete conductive networks were observed in UHMWPE/CNT composites in the following MW sintering process, revealing that a perfect segregated structure was successfully constructed. The segregated UHMWPE/CNT composites exhibited an excellent electrical conductivity and EMI shielding performance of 49.3 S/m and 50 dB, respectively, along with a low percolation threshold of 0.10 vol%. Meanwhile, benefiting from the volumetric heating, an ideal mechanical property was also obtained in prepared composite by MW sintering. Compared with the conventional molding method, MW-assisted sintering shows its unique advantages, including better structural construction, shorter processing time, and lower energy consumption, which provides an efficient and environment-friendly method to fabricate CPCs with superior conductive and EMI shielding performance.