Abstract

Traditionally flexible body armor has been developed by using a mixture of silica and Polyethylene glycol (PEG) impregnated with Kevlar fabric. Our recent experiments have indicated that if silica particles are functionalized with a silane coupling agent such as trimethoxysilane, we can achieve better stab resistance of the fabric composites. This happens due to the formation of siloxane bonds induced by the alkoxy group present in silane and hydroxyl functional groups in silica nanoparticles. The organo-functional group of silane therefore allows establishment of a direct covalent connection between the silica particle and the carrier polymer, PEG. In an attempt to examine the role of PEG, armor composites were then fabricated with silica and silane alone without addition of any PEG. The performance was even better at this time suggesting that silane, silica and Kevlar can be an armor system without the presence of PEG. This prompted us to introduce a fixative cross-linker (Glutaraldehyde, or Gluta) which would not only increase the bonding between particles through silane, but also induce a linkage with the amide groups present in the Kevlar fabric. The performance of the resulting armor composites was phenomenal – we were able to demonstrate that there was no penetration up to 220 J-cm²/g which superseded the previous systems by a factor of four. Details of armor development and their performance evaluation will be presented.

Please see the Seminar Announcement.