Mechanical, electrical, and damage self-sensing properties of basalt fiber/carbon nanotube/poly (arylene ether nitrile) composites

Basalt fiber reinforced polymer composites (BFRP) are widely applied in sectors such as aerospace, rail transportation, construction, and energy. However, developing BFRP with effective damage self-sensing capabilities remains a major technical challenge. This study utilized basalt fiber (BF) as both a reinforcement and volume exclusion phase to improve the mechanical and electrical properties of BF/carbon nanotube (CNT)/polyarylene ether nitrile (PEN) composites, aiming to achieve damage self-sensing functionality. The CNT content in BF/CNT/PEN was fixed at only 0.5 wt%. As the BF content increased from 10 wt% to 50 wt%, the mechanical properties of the BF/CNT/PEN composites improved, with tensile strength, flexural strength, and flexural modulus increasing by 39.0%, 26.3%, and 167.7%, respectively. Additionally, the electrical conductivity of composites with 40 wt% BF increased by three orders of magnitude compared to that with 10 wt% BF. Combined with acoustic emission (AE) monitoring, it was confirmed that composites with 40 wt% BF demonstrated excellent damage self-sensing and fracture warning capabilities under tensile and bending stress. This study not only improved the mechanical properties but also enhanced the electrical conductivity of the BFRP without the need for additional conductive materials, thereby ensuring effective damage self-sensing functionality. These results offer valuable insights for developing high-performance, multifunctional BFRP.