Abstract
Nanoalumina particles, prepared by autoignition of aluminum nitrate with urea, were made compatible with the styrene—acrylonitrile copolymer syrup (in its own monomer) by chemical modification using methacrylol isocyanate. The polymer syrup prepared this way was applied between two PMMA sheets of 10 cm × 10 cm × 2 mm dimension each and the composite thus prepared was tested with a bullet firing machine as well as a drop weight impact testing machine. The impact strength measurements of a two plate composite using both these procedures showed that the impact resistance was found to double in the case of a chemically modified nanoalumina composite. The impact energy needed to fracture the multilayered composites can be modeled by a quadratic expression involving the number of layers. A ten-layer PMMA sheet can withstand as much as 110 J impact energy without any noticeable damage. The ten-layer composite was not penetrated by a 0.32 IOF revolver having a bullet mass of 9.9 g and muzzle velocity of 236 ± 7 m/s (muzzle energy of 275 J). The eleven-layers composite was further tested by a Sub Machine Gun Carbine 9 mm 1A1, having a bullet mass of 11.9 g and muzzle velocity of 390 m/s (muzzle energy of 900 J) which produced an ordinary indent with no penetration.
Get full access to this article
View all access options for this article.
