LAUSR

MATERIALE PLASTICE ♦ 55♦ No. 3 ♦ 2018 315 During conflict situations, the combat staff is exposed to a wide variety of aggressions, such as temperature and pressure variations, and dynamic impacts (from ammunition or fragments). Textiles used in the manufacture of the military uniforms and devices have always played an important role in defending the military against these hazards, and an adequate level of individual protection equipment (IPE) is required [1,5]. The protective clothing can be divided in air permeable (widely used for military purposes) or air impermeable (when a polymer-based membrane or film is employed as a ûlter to prevent toxic chemicals to penetrate) [2,3], such as polyesters, polyether amides or polyurethanes [2,4]. In this respect, the present study aimed at the possibility of using some novel composites of polymers and fibrereinforced polymer composite materials for military application: reducing blunt trauma for ballistic protection equipment. The polymer matrix is polyurea and the considered fibres are functionalized multi-wall carbon nanotubes (MWCNTs). The reinforcement of a polymeric matrix with high strength and modulus fibres using the viscoelastic displacement of the matrix under stress transfers the load to the fibre; this resulting in a high strength and a high modulus composite material [4-12]. Polyurea is a flexible aminoplast, with highly valued properties in terms of softness and flexibility, which, due to its effective energy absorption properties, is commonly used as protective coating on concrete or steel structures. Polyurea coatings combine strength with extensibility; the material being highly resistant, with low flammability and known to mitigate abrasive wear, blast and fragmentation [13-25]. From the typical application as a protective coating of concrete and steel structures, this elastomeric coating has been proven to withstand not only abrasion, but also rapid loadings like impacts, collisions or explosions [1323]. The aim of the composite is to produce a two-phase material in which the primary phase, that determines the stiffness, is fibre-shaped and is well dispersed and bonded and protected by a secondary phase, the polymeric matrix. The fibre-reinforced polymer composite materials mechanical and physical properties are clearly determined Synthesis and Mechanical Properties of Polyurea-Based Hybrid Composites for Ballistic Individual Protection