Evaluation of New Bio-Based Hybrid Composite Materials Reinforced with Basalt Fiber and Recycled Carbon Fiber

Developing green materials is essential for the transition toward more sustainable engineering solutions. Among these, biopolymers and their composites represent promising alternatives to petroleum-based polymers due to their biodegradability, lower toxicity, and potential cost-efficiency—especially when derived from waste. In this work, we explore the feasibility of using a bio-based resin, epoxidized resveratrol (RESEP), reinforced with continuous basalt fibers as a sustainable composite for non-structural components in railway vehicles.

Three composite laminates were fabricated via the hand lay-up method, a reference laminate (RESEP + basalt), a laminate with 5%wt DOPO (a flame-retardant agent), and a laminate with 7.5%wt mechanically recycled carbon fiber (RCF), to obtain smart materials by developing electrically conductive composites. The composites were characterized by density measurements, mechanical and thermomechanical testing, and fire resistance evaluations. Additionally, the RCF-reinforced laminate was assessed for structural health monitoring (SHM) capabilities and de-icing performance via Joule heating.

Our results show that the RCF-reinforced laminate combines good mechanical behavior with added functionalities such as SHM and active de-icing, despite slight mechanical trade-offs. In contrast, DOPO inclusion negatively impacted mechanical and fire performance. Here, a significant decrease in interlaminar shear strength was observed, likely due to the increased resin viscosity, hindering fiber impregnation. These defects compromise both mechanical integrity and fire resistance. Consequently, the RCF laminate is proposed for external applications requiring multifunctionality, while the reference laminate is more suitable for fire-sensitive interior uses.

This study supports the advancement of sustainable, high-performance composites for the transportation sector in alignment with circular economy and emission reduction goals.