UV-Curable Polythiophene-Modified Carbon Nanotube Films for High-Performance EMI Shielding with Damage-Repairable Capability

Carbon nanotubes (CNTs) are widely recognized for their potential in electromagnetic interference (EMI) shielding applications. However, their integration into UV-curable resin systems to fabricate shielding films remains underexplored. In this study, UV-curable polythiophene derivative-modified CNTs (PMTA-CNTs) were synthesized and incorporated into a UV-curable polyurethane acrylate (PUA) matrix to fabricate conductive, flexible films. The resulting composite film containing 12.5 wt % CNTs (PUA–PMTA-CNT 12.5%) exhibits a robust three-dimensional conductive network structure with covalent bonding, achieving a tensile strength of 31.5 MPa, elongation at break of 116.2%, and an electrical conductivity of 1463 S/m. Notably, it demonstrates an EMI shielding effectiveness (EMI SET) of 50.6 dB, meeting stringent commercial requirements. Leveraging UV-curing technology, mechanical damage to the film was efficiently repaired, restoring the EMI SET to 50.1 dB. This work presents a promising route for developing high-performance, UV-curable, and repairable EMI shielding materials suitable for use in harsh environments.