Bulletproof performance of polyimide/UHMWPE fiber hybrid reinforced composites

Aiming at the deficiency of high back-face signature (BFS) of ultra-high molecular weight polyethylene (UHMWPE) fiber-reinforced ballistic composites, a series of polyimide (PI) and UHMWPE fiber hybrid composites were prepared by making full use of the advantages of high temperature resistance and high modulus of PI fibers in this study. The effects of layer structure and mixing ratio on the specific energy absorption (SEA) and BFS values of the hybrid composites and the protective mechanism were investigated. The results show that the use of PI fibers can effectively limit the BFS without affecting the SEA value. The bipolar layer structure (H3, UHMWPE/PI) and the sandwich layer structure (H4, PI/UHMWPE/PI) exhibit positive mixed effect. SEA and BFS values of the two structures can reach 193.2 J·m²/kg, 17.40 mm and 208.9 J·m²/kg, 17.77 mm, respectively, demonstrated excellent bulletproof performance.