Effects of plasma pre-treatment and polyurethane/IF-WS2 nanocoating on mechanical and viscoelastic properties of UHMWPE yarns

Ultra-high-molecular-weight polyethylene (UHMWPE) fiber is highly favored for fiber-based ballistic composites due to its high strength-to-weight ratio and flexibility. However, its poor adhesion to matrices largely limits its application in polymer composites. Also, the weight of ballistic armor produced from these fibers is still very high and there is a need to improve their performance to enable the use of lighter-weight armor. In this work, it was observed that applying plasma pre-treatment and waterborne polyurethane (PU)/inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticle coating could significantly increase the toughness, energy to break, and maximum load of UHMWPE yarns. The corresponding properties of the plasma pre-treated and coated fibers increased up to 31.6%, 50.9%, and 33.3%, respectively. In addition, high wash durability of the coating was obtained with up to 92% weight retention after washing. Optimum properties were observed with the coating components of 15% PU (PUA type), 6% IF-WS2, and water medium (SA3 nanocomposite). Moreover, plasma pre-treatment induced oxygen-containing functional groups on the fibers, which significantly improved the mechanical, viscoelastic, and wash durability properties of the final UHMWPE/PUA/IF-WS2 composites.