Fibers-induced segregated-like structure for polymer composites achieving excellent thermal conductivity and electromagnetic interference shielding efficiency

With the rapid development of new-generation wireless communication technologies and portable intelligent electronic devices, the development of composites with excellent thermal conductivity and electromagnetic shielding properties has become an urgent challenge. In this work, a unique fibers-induced segregated-like structure strategy for fabricating thermoplastic polyurethane/polydopamine/silver (TPU/PDA/Ag) composites film with high thermal conductivity (TC) and excellent electromagnetic interference (EMI) shielding performance is demonstrated via electrospinning-electroless depositing-pressing technology. The TPU/PDA/Ag composites film exhibit excellent in-plane TC of 20.9 W/(m⋅K) at 75 wt% Ag loading, which shows excellent thermal management capability as heat spreaders of high-power light-emitting diode (LED) modules in practice. Meanwhile, the composites film presents outstanding EMI shielding efficiency of 109 dB (8.2–12.4 GHz) with a thickness of 45 μm and prominent EMI shielding reliability after 1000 cycles of bending. In addition, the composites film shows good tensile strength (12.1 MPa), elongation at break (108.0%), and toughness (11.59 MJ/m 3 ). The obtained TPU/PDA/Ag composites film achieves the desired balance among thermal conductivity, EMI shielding, and mechanical properties, indicating broad application prospects in new-generation wireless communication technologies and portable intelligent electronic devices.