Impact resistance of aramid honeycomb tandem sandwich composites reinforced with TiB2

Abstract

A novel composite tandem sandwich structure made of aramid fabric and aramid honeycomb, impregnated in a matrix of epoxy resin combined with poly (vinyl butyral), PVB, is proposed. The composite was additionally reinforced with a small concentration of titanium diboride nanoparticles, TiB2, to study its effect on impact resistance. Sandwich composite samples were fabricated by impregnating the aramid fabrics and honeycomb in subsequent layers with the system epoxy/PVB/TiB2. Their mechanical behavior was examined through three-point bending test, Charpy impact test, and compressive test. The chemical reaction between PVB and epoxy resin, and chemical inertness between the nanoparticles and the other constituents were confirmed by FTIR analysis. The flexural strength and stiffness increased by 27.6% and 62.5%, respectively, in the presence of TiB2 reinforcement. Impact tests showed increase of 104% in impact toughness in the case of samples with TiB2. Nano TiB2 did not increase compressive strength of the proposed sandwich structure, but it improved its stiffness and reduced the permanent deformation. The achieved improvements in mechanical resistance make this new composite structure a promising candidate for automotive, airspace, naval, civil engineering, sports equipment industry, and for use in defense technologies.