标题：Ultrahigh strength poly(lactic acid) composites with superior EMI shielding performance enabled by synergistic effect of short carbon fibers and carbon nanotubes
作者：Hai-Hang Xie, Yong Lu, Xiao-Li Zhao, Jian-Bing Zeng , Ming Wang , Yi-Dong Li
摘要：Currently reported carbon materials filled PLA composites are often limited by either insufficient electromagnetic interference shielding efficiency (EMI SE), or poor mechanical strength, and/or complex fabrication procedures. To address these challenges, we present a novel approach that advances the synergistic effect of short carbon fibers (CFs) and carbon nanotubes (CNTs) through simple melt mixing to enhance the performance of PLA composites. Our findings demonstrate that the formation of a robust CF-CNT hybrid network significantly improves electrical conductivity (EC), EMI shielding efficiency, and mechanical strength compared to both PLA/CF and PLA/CNT binary composites. We prepared a series of PLA/CF/CNT composites with varying contents of CFs and CNTs and systematically investigated their effects on morphology, rheological properties, EC, EMI shielding performance, and mechanical properties. We also compared these properties to those of PLA/CF and PLA/CNT binary composites. Notably, our optimal formulation, PLA/30CF/1CNT containing 30 wt% CFs and 1 wt% CNT, exhibited superior overall properties, including an EC of 577.8 S/m, EMI SE of 58.0 dB, tensile strength of 186.27 MPa, and Young’s modulus of 12.47 GPa. These overall superior properties overwhelm those of most recently reported carbon materials-filled conductive PLA composites. Our results underscore the effectiveness of the synergistic effect between CFs and CNTs, highlighting the potential of the conductive PLA-based composites as sustainable and high-performance materials for EMI shielding applications.
