Effects of temperature, pressure, and aging on the polymer transitions of plastic211 bonded explosives

摘要

Plastic bonded explosive (PBX) contain 5-wt% polymer, plasticizer, and stabilizer211u001eas binder. The temperature of the glass transition (Tg) determines if the binder 211u001ewill reduce or increase the sensitivity of the PBX to impact. A soft polymer, 211u001esuch as Estane, a polyester/polyurethane black polymer with Tg below the 211u001etemperature of use, reduces the sensitivity; however, it must retain the 211u001emechanical strength necessary for dimensional stability throughout processing and 211u001eits lifetime. One binder studied was 50-wt% Estane and 50-wt% plasticizer. Glass 211u001etransitions and other polymer relaxations were found by temperature modulated DSC 211u001efor PBX before and after pressing at 90degC, which is above the softening 211u001etemperature of the binder; and for Estane and PBX under aging conditions. PBX 211u001eprepared with aged Estane was also tested for changes in the binder Tg.