Progress on Zirconia-Polyurea Matrix Hybrid Composites
Technical Report,01 Oct 2018,29 Aug 2019
CCDC Army Research Laboratory Aberdeen Proving Ground United States
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In state-of-the-art ballistic body armor, laminate composites comprising ceramic plates with metallic and ultrahigh molecular weight polyethylene fiber composite backing layers using adhesives have the potential to achieve lightweight ballistic efficiency. Here, we aim to exploit shock impedance optimization at the bilayer interface, particularly between ceramic and adhesive layers. This study investigates the incorporation of zirconia particles into polyurea elastomers to form hybrid composites as a potential candidate structural adhesive material. Pristine zirconia particles are first thoroughly premixed with an oligomeric diamine, also a reactant for polyurea, as an alternative pathway without organosilanes for surface functionalization. Interface interactions between zirconia and polyurea in the matrix are revealed via attenuated total reflectance-Fourier transform infrared spectroscopy, where a shift and broadening of the urea-carbonyl stretching and an increase in relative intensity of the corresponding disordered versus ordered NH stretching are shown in hybrid composites versus bulk polyurea. This corroborates well the presence of relaxation broadening in the tan delta data in dynamic mechanical analysis, where a shift of the soft phase glass transition toward higher temperatures is evidenced in hybrid composites in contrast to a well-defined segmental relaxation observed in bulk material. The composition dependence of the dynamic storage modulus is also elaborated.
- Laminates and Composite Materials