Synthesis and Performance of Nano-Processed Terephthalic Acid Smoke Obscurants

Terephthalic acid (TA) smoke obscurant was developed by the U.S. Army as an environmentally benign replacement to hexachloroethane and white phosphorus based smoke for use in the M-83 grenade and M-8 smoke pot.  Although TA smoke mix is a safer pyrotechnic smoke with respect to inhalation, it is a less effective visual obscurant than the legacy mixes.  Visual obscurants are deployed to conceal ground movements from an enemy line of sight.  It was hypothesized that reducing the particle size of the TA smoke mix will cause a more complete burn and thus create a thicker visual obscurant cloud.  Here, the particle size of terephthalic acid smoke mix was reduced into the nano-regime through high energy milling.  The effect of various processing parameters is presented; the nano-processed smoke mixes are characterized for particle size, morphology, and sensitivity.  The smoke mixes were pressed into large-scale grenade configurations.  Large-scale chamber and live-fire testing was performed, and the results will be discussed and compared to legacy obscurants.