Novel Epoxy‐Enhanced Shear‐Thickening Gel Materials for Advanced Impact Protection

ABSTRACT Low‐crosslinked polyborosiloxane (PBS)‐based shear thickening gels (STGs) have attracted considerable attention in ballistic and stab protection fields because of their excellent impact hardening performance and self‐healing capabilities. However, the cold‐flow characteristic limits morphological stability and low modulus compromises impact resistance, which to some extent hinders their application in actual protective equipment. Here, we first report a series of epoxy resin (EP) /PBS shear‐thickening gels for low‐speed impact protection fabricated via a one‐pot method. The obtained EP/PBS STGs exhibited ideal characteristics, such as high elastic modulus (1.6 × 10 5 ~ 2.4 × 10 5 Pa at 100 Hz) and compressive modulus (760 ~ 2400 Pa at 0.25 s‐1). We validated these STGs morphological stability and self‐healing capabilities; these STGs showed reduced height (~23%) after 1 h and healing efficiencies were measured as (94.1% ~ 84.5%). Further tests showed that under r = 0.1, the impact resistance of EP/PBS reached optimal levels, especially under higher strain rates, where its impact energy absorption capacity was significantly superior to traditional materials. As helmet cushioning, EP/PBS ( r = 0.1 r denotes the mass ratio of EP to PDMS‐OH) reduced the maximum impact force by 31% compared to traditional EVA. These improvements in performance are mainly attributed to the addition of EP, which forms a denser crosslinked network structure, enhancing the material's rigidity, elasticity, and energy absorption capacity. This research provides new ideas and theoretical support for designing high‐performance protective materials.