Study on the mechanical properties and ballistic resistance of interface-modified fabrics with environmentally friendly shear thickening liquid

Based on the modification of industrial solid waste and surface grafting of functional groups to prepare new ballistic composites with green shear thickening functionality, ammonia-modified silica (NH₄-SA) particles were successfully prepared from industrial solid waste through APTMS surface modification, and the modified NH₄-SA was used as the shear thickening dispersed phase to regulate the green shear thickening solution, and in order to better achieve the grafting loading of the particles of the dispersed phase, the aramid fabric (AF) was metal ion modified. Ballistic resistance was tested by combining a solid waste-based modified shear thickening fluid (NH₄-SA@STF) with a metal ion modified AF fabric. Characterization tests confirmed that NH₄-SA@STF exhibited a significant shear thickening effect due to the addition of reactive functional groups on the surface of NH₄-SA. Yarn pull-out tests showed that NH₄-SA@STF/Fe-AF had a 4-fold increase in pull-out force and better friction properties compared to AF fabrics. Ballistic tests demonstrated that NH₄-SA@STF increased the ballistic limiting velocity (V_bl) of AF fabrics from 52 m/s to 99 m/s. Both layer impregnation modification and individual impregnation treatment of each layer showed strong ballistic performance, indicating that NH₄-SA@STF/Fe-AF composites exhibited superior ballistic performance compared to AF fabrics. The doping of NH₄-SA enhanced the friction between the yarns and increased the load-bearing area of the fabric, resulting in improved ballistic performance of NH₄-SA@STF/Fe-AF composites. The study successfully achieved the regulation of ballistic properties in NH₄-SA@STF/Fe-AF composites, providing a promising approach for the development of new ballistic materials with green shear thickening functionality.