Preparation of Self‐Healing Thermoplastic Polyurethane/Carbon Nanotube Nanocomposites for Electromagnetic Shielding

ABSTRACT Electromagnetic interference (EMI)‐shielding nanocomposites are prone to damage during long‐term use, compromising device performance. Consequently, extensive attention has been paid to materials that combine reliable EMI shielding with self‐healing capabilities. In this study, a flexible conductive thermoplastic polyurethane (TPU) nanocomposite integrating EMI shielding and self‐healing functionalities was facilely developed through a solution blending process followed by simple casting. In the X‐band frequency range, the nanocomposite containing 15.0 wt% Fe 3 O 4 @multiwalled carbon nanotubes (Fe@CNT) exhibits an outstanding EMI shielding effectiveness of 37.6 dB. After three cut–repair cycles, the EMI shielding effectiveness recovers to 34.6 dB, retaining 92.3% of its initial performance. The TPU‐Fe@CNT (TPUF) nanocomposite exhibits reproducible tensile properties, demonstrating excellent healing repeatability (healing efficiency: 96%) in elongation at break. Thus, this work presents a self‐healable EMI shielding nanocomposite, showcasing its potential for applications in wearable electronics where durability and long‐term reliability are paramount.