目的 开发具有优异屏蔽效率、轻质且热稳定性良好的电磁屏蔽材料。方法 以聚酰亚胺(PI)为聚合物基体，聚吡咯(PPy)为添加相，采用静电纺丝-低温原位聚合技术制备PPy/PI电磁屏蔽复合膜。通过在薄膜内部的多孔结构中构建致密的导电网络，赋予复合膜优异的导电性和高效的电磁屏蔽效能。结果 在聚合PPy浓度为0.1 mol/L时，复合膜的电导率和电磁屏蔽效能分别为2.23 S/cm和26.04 dB，且其单位厚度电磁屏蔽效能可达到110.81 dB/mm，展现出优异的电磁屏蔽性能。结论 PPy/PI复合纤维膜表现出良好的力学性能(拉伸强度为11.73 MPa)、优异的热稳定性(>400 ℃)和力学传感性能，具备在恶劣环境下广泛应用的潜力。

The work aims to develop electromagnetic shielding material that is both highly efficient in its shielding capabilities, lightweight, and offers good thermal stability. In this study, PPy/PI electromagnetic shielding composite films were fabricated using the electrostatic spinning-low temperature in-situ polymerization technique with polyimide (PI) as the polymer matrix and polypyrrole (PPy) as the reinforced phase. By establishing a dense conductive network within the film's porous structure, the composite film exhibited excellent electrical conductivity and efficient electromagnetic shielding effectiveness. The conductivity and electromagnetic shielding effectiveness of the composite film were 2.23 S/cm and 26.04 dB when the PPy of.1 mol/L was polymerized, and the effectiveness of its electromagnetic shielding per unit thickness could reach 110.81 dB/mm, which was a remarkable performance for electromagnetic shielding. Additionally, the PPy/PI composite fiber film has excellent mechanical properties (with a tensile strength of 11.73 MPa), excellent thermal stability (>400°C) and mechanical sensing properties, with the potential to have a variety of uses in harsh environments.