Mechanical and Electromagnetic Shielding Properties of Modified CNT ‐Reinforced Basalt Fiber/Epoxy Composites

Basalt fiber (BF)‐reinforced epoxy (EP) composites exhibit excellent mechanical and thermal stability, yet their limited multifunctionality and poor interfacial properties restrict their use in high‐end electromagnetic shielding applications. To address these challenges, this study employed hand‐lay‐up molding to fabricate functionalized carbon nanotube (f‐CNT)‐reinforced BF‐EP composites, systematically investigating the effects of f‐CNT concentration (0–15 wt%) and laminate structure (3–30 layers) on multidimensional properties. Results show that surface wettability is controllable, with water contact angle increasing from 30.8° to 68.2°, indicating optimized interfacial compatibility. The incorporation of modified CNTs, combined with the basalt fiber framework, enhances thermal stability, achieving a char yield of 79.32%. Mechanical properties are improved: flexural strength from 470.6 to 764.6 MPa (+62.5%), and tensile strength from 318.2 MPa to 332.0 MPa (+4.3%). At 15 wt% f‐CNT concentration, sheet resistance drops to 0.20 kΩ, and electromagnetic shielding effectiveness of the 30‐layer structure reaches 20–23 dB (X‐band), with the shielding mechanism shifting to absorption‐dominated behavior. This study develops a structure–property integrated composite, providing a key basis for designing high‐performance electromagnetic shielding materials.