Embedding Conductive Composite Film for Out‐of‐Oven Manufacturing of Basalt Fiber‐Reinforced Epoxy Composites With Damage Self‐Sensing Ability

ABSTRACT The high energy consumption of the conventional curing process and the limited structural intelligence in fiber‐reinforced composites are still significant challenges. Herein, a sandwich‐structured carbon nanotube/polypropylene/carbon nanotube (CPC) film is developed by vacuum filtration and hot pressing. The CPC film achieved a tensile strength of 9.86 MPa, a 371% enhancement over neat carbon nanotube (CNT) films. The CPC film exhibits excellent Joule heating performance with a high saturation temperature (97.5°C), a high heating rate (167°C/min) and uniform and stable heating after 40 abrasion cycles. Moreover, the resin curing process can be monitored by embedding CPC film into the surface of basalt fiber‐reinforced polymer composites (BFRPs). The infiltration of resin into the CNT network leads to a significant change in electrical resistance, with a maximum relative resistance change (ΔR/R ₀ ) of up to 797%. This integration also enables out‐of‐oven curing, which reduces energy consumption by 96%, and confers BFRPs with damage self‐sensing capability without affecting their flexural properties. The developed composite can monitor deformation and provide failure warnings, with a maximum gauge factor (GF) of 59 when the film is embedded on the lower surface. This study introduces a novel strategy for eco‐friendly manufacturing of sustainable fiber‐reinforced composites with damage self‐sensing.