WS2 nanostructures as thermo-mechanical reinforcement of composite materials for advanced applications

Abstract

As one of transition metal dichalogenides, tungsten disulphide (WS2) is well known for its solid lubricating behavior, but besides this feature, it exhibits extraordinary thermal stability and mechanical resistance. The outstanding mechanical strength of WS2 is most pronounced when it comes in form of multi-layer hollow nanoparticles and nanotubes: inorganic fullerene-like nanoparticles and inorganic nanotubes, denoted as IF-WS2 and INT-WS2, respectively. These structures have extraordinary shock resistance properties, pressure and heat resistance, that can be exploited for a variety of applications. They have been studied as reinforcing fillers of various polymers, but they might be also added as reinforcement of matrix in more complex composites, like CFRPs. Our research aimed to examine their reinforcing effect on laminated composites based on aramid fabric and poly(vinyl butyral), PVB, intended for demanding applications: in personal protection equipment, ballistic protection, sports equipment, automotive, nautical and aircraft engineering. WS2 nanostructures have been incorporated in PVB by temporary dissolving in ethanol, by ultrasonication and intensive mechanical mixing. After impregnation of aramid fabrics ethanol would evaporate, and layers of aramid with thermoplastic binder PVB would be integrated by hot pressing. SEM analysis confirms the uniform distribution of WS2 nanostructures in the prepared composite material. DSC analysis reveals the effect of WS2 addition on thermal resistance of the new material, while PVB/aramid mechanical resistance was examined using DMA, impact test and tensile test. IF- WS2 has imported higher thermal resistance and ductility improvement, while INT-WS2 has significantly improved tensile and impact strength of the composite.