Construction of an organic/inorganic coating on basalt fiber to reinforce mechanical properties and helical structural stability

Abstract Basalt fibers (BFs), as high-performance fibers, exhibit exceptional mechanical properties, chemical stability, thermal retardant, flame resistance. However, their adoption in textiles is significantly hindered by fiber fracture and irritation, due to their high modulus, low toughness, and brittleness characteristics. In this study, a composite coating of waterborne polyurethane and nano-SiO 2 was used for the BF surface modification, enhancing their mechanical properties and helical structural stability through the synergism of soft and rigid phases, and leading to the successful preparation of basalt yarns. The composite coating is strongly adhered to the fiber surface via electrostatic interactions, intermolecular forces, and adhesion, well contributes to fiber protection and cohesion force enhancement. The tensile strength and helical properties of BFs modified with 0.75 wt% WS coating increased by 21.9% and 225.1%, respectively. The increased roughness resulted in both static and dynamic frictional coefficients improved by 160.8% and 191.7% respectively, which obviously improved fibers' cohesion force. The yarns produced from coated fibers exhibited a compact structure and improved abrasion resistance while increasing tensile strength by 26.1%. Additionally, the coated fabrics maintained good skin compatibility even after 3000 cycles of rubbing. We utilized a simple coating method to alleviate the BFs’ brittleness, improve helical structural stability and wearability, and offer a new way for the wearability of BFs to expand their application potential in textiles and clothing.