Synergetic control of multi‐level interface structure of basalt fibers by plasma and chemical functionalization to enhance the mechanical, thermal and interfacial performances of PBZ composites

The composites of polybenzoxazine (PBZ) containing functionalized plasma treatment basalt fibers ( f P‐BFs) were fabricated through in‐situ polymerization‐mixing technique. f P‐BFs is an effective reinforcement material that can improve the mechanical, thermal, and interfacial properties of composites. Surface activation of f P‐BFs can be enhanced through plasma modification, which improves the interaction between f P‐BFs and 3 ‐aminopropyltriethoxysilane. A systematic study on f P‐BFs/PBZ composite showed that a processing power of 300 W, a processing time of 5 min, and a fiber content of 9% can achieve good comprehensive mechanical properties. Thermogravimetric analysis results showed that f P‐BFs‐7/PBZ has the highest thermal stability, and its carbon residue rate, decomposition temperature and thermal decomposition activation energy are 36.80%, 452.2 °C and 133.56 kJ/mol, respectively. The dynamic mechanical analysis experiment showed that the addition of f P‐BFs improved the T g of the composites. Among them, f P‐BFs‐5/PBZ showed the highest T g , reaching 233.2 °C. Highlights Plasma treatment produced multi‐level structure of basalt fibers ( f P‐BFs). Polybenzoxazine (PBZ)/ f P‐BFs composites showed excellent performance. Interfacial bonding mechanism between f P‐BFs and PBZ was elucidated. Interfacial interactions between BFs and PBZ contributed to property enhancement. This work provided a green fabrication strategy of PBZ composites.