Performance Analysis of Chitosan Covalently Grafted Basalt Fiber Composites

Abstract

To improve the inferior interfacial compatibility between basalt fiber and epoxy resin, and enhance the mechanical and insulating properties of composites, silane-pretreated basalt fibers were modified with chitosan solutions of varying concentrations. The effects of modification on fiber and composite performances were systematically explored. The results show that chitosan can be covalently anchored on basalt fiber surfaces to optimize fiber–resin interfacial adhesion. The 2 g/L chitosan-modified sample (CTS2-BFRP) achieves the best overall performance. Relative to the blank group, its fiber total surface energy and monofilament tensile strength are increased by 70.59% and 36.42%, while the breakdown strength and surface flashover voltage are elevated by 29.73% and 26.47%. Correspondingly, transverse tensile and flexural strengths are improved by 25.56% and 12.70%. This work clarifies the intrinsic correlation among surface modification, interfacial structure, and macroscopic properties, and provides experimental and theoretical support for the performance optimization of chitosan-modified basalt fiber/epoxy composites.