A chemically stable syrup of poly(methyl methacrylate) in its monomer was prepared with a suitable dual-initiating system. Nanoalumina particles were prepared by the autoignition of aluminum nitrate with urea and were made compatible with the organic medium by chemical modification with methacrylol isocyanate. The polymer syrup prepared in this way was applied between two poly(methyl methacrylate) sheets (each 10 cm 3 10 cm 3 2 mm), and the composite thus prepared was tested with a bullet-firing machine and a drop-weight-impact testing machine. The impact strength measurements of the two-plate composite from both of these procedures showed that the impact resistance doubled in the case of nanoalumina. The modeling of the damage to the multilayered composite by the critical impact energy was performed with the relation E ¼ pn 2 1 qn 1 r, where E is the impact energy, p, q, and r are constants, and n is the number of layers. Experiments showed that the presence of nanoparticles in the adhesive increased the value of the constants. The 10-layer composite was further tested with a 0.32 Indian Ordinance Factory (IOF) revolver with a bullet mass of 9.9 g and a muzzle velocity of 236 6 7 m/s (muzzle energy ¼ 275 J) from a 10-m distance, which produced an ordinary indentation with no penetration.
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 AE 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.
Polymer syrup of polymethyl methacrylate and polystyrene reinforced with 2% non settling nanoalumina particles was prepared by dual initiating system containing benzoylperoxide (BPO), azo-bisisobutyro nitrile (AIBN) and dimethylaniline (DMA). Nanoalumina particles were prepared using autoignition of aluminum nitrate and urea. Nanoalumina particles show the tendency of agglomeration in the polymer matrix because of the presence of hydroxyl groups on its surface. To get better dispersion in polymer matrix, the alumina surface was treated with methacrylol isocyanate, synthesized by the reaction of methacrylol chloride and sodium azide in the presence of dry benzene at 0 degrees C. The polymer syrup prepared this way was applied between two PMMA sheets of 10 cms x 10 cms x 2 mm dimensions each and the composite thus prepared was tested with Bullet Firing Machine as well as Vertical Drop Weight Impact Testing Machine. The impact strength measurements of two plates composite using both these procedures showed that the impact resistance was found to double in case of nanoalumina. The composite of ten layers and of eleven layers was further tested by 0.32 IOF revolver and Sub Machine Gun Carbine 9 mm 1A1 respectively from 10 m distance which produced an ordinary indent with no penetration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.