Spall strength measurement of spray polyurea and alumina reinforced spray polyurea composite

Spray-formed polyurea composites filled with basalt powder as inorganic waste filler

“…The addition of the filler significantly reduced the presence of pores in the structure of composites, compared to unmodified PUA. This is due both to the variation in the composition's viscosity and the effect of inhibiting pore nucleation, similarly to the effect described by Oddy et al in the case of PUA-alumina-filled composites [21]. The increase in viscosity of the composition filled with BP probably caused a change in the course of the spraying process.…”

“…This can be accomplished by the use of micrometric-sized inorganic or metallic fillers. Oddy and co-workers [21] proposed the use of irregular alumina particles as a reinforcement of polyurea spray coating. Their investigations showed that alumina-reinforces samples were characterised with improved resistance to void nucleation and improved the spall-strength of the polyurea.…”

Polyurea for Blast and Impact Protection: A Review

“…Reinforcing fibers are widely adopted to improve the mechanical properties of polymers to achieve more load-carrying capacity [71][72][73]. High-strength and high-modulus polymer composites are produced by reinforcing the polymer matrix with high-strength and high-modulus fibers, the reinforcing fibers are employed to increase the strength and stiffness of the material, and the load is transferred to the fibers via the viscoelastic displacement of the matrix under stress [74]. The reinforcing fibers that are commonly used for enhancing performance are glass fiber (GF) [20,39,[70][71][72][73]75], basalt fiber (BF) [22,23,76,77] and carbon fiber (CF) [78][79][80][81].…”

“…Alumina particles are another reinforcing filler for polyurea. Oddy et al [74] added irregular alumina particles to the polyurea as a reinforcing material and found by SEM that the addition of alumina particles appeared to inhibit the tendency to entrain and trap air in the polyurea during the spraying process, achieving the elimination or reduction in porosity in the pure sample. Figure 7 shows SEM images of the middle plane of the neat polyurea sample and the alumina-reinforced polyurea sample.…”

A study on the Ballistic and Abrasive Response of Polyurea Coatings on Ballistic Fabrics

“…This process entraps large amounts of air within the polyurea coating. A pristine spray polyurea was compared to a spray polyurea reinforced with micron-scale alumina particles [71]. It was found that the polyurea reinforced with alumina had greatly increased spall strength compared to the pristine polyurea.…”