Interfacial modification to improve the mechanical performance of basalt fiber/epoxy 3D woven composites

This study aims to improve the interfacial and mechanical properties of basalt fiber (BF) 3D angle interlocking woven composites (3D-AWCs). BFs inherently exhibit poor interfacial properties due to their smooth surface and lack of functional groups, resulting in low mechanical performance in composites. To address this issue, functionalized carboxylated multi-walled carbon nanotubes (KH570-MWCNTs) and polydopamine (PDA) were used to modify the surface of BFs, enhancing surface roughness and increasing friction between the reinforcement and the matrix. Modified and unmodified 3D woven basalt fabrics served as reinforcing materials, with epoxy resin (EP) as the matrix, and 3D-AWCs were fabricated through a vacuum-assisted resin transfer molding (VARTM) process. Tensile, bending and impact tests were conducted to evaluate the mechanical performance of the modified composites. The results showed significant improvements: maximum warp and weft tensile loads increased by 23.4% and 34.8%, respectively, while warp and weft bending loads increased by 19.4% and 30.9%. Moreover, the maximum impact load increased by 151.6%. The modified composites also exhibited good mechanical integrity with no delamination observed. These findings highlight the effectiveness of interfacial modification in enhancing the mechanical properties of basalt woven composites, making them more suitable for applications in aerospace, automotive and construction industries where superior mechanical performance is essential.