Pot Life Problem and its measure with a reduced smoke propellant production

Typical reduced smoke type composite propellants mainly composed of hydroxyl-terminated polybutadiene (HTPB) and ammonium perchlorate (AP) have a drawback that these propellant grains have a high response function of the burning rate to cause acoustic pressure oscillation. The addition of a small fraction (0.5% ∼ 1.2wt%) of zirconium (Zr) or zirconium oxide powders to propellant compositions has been known to be effective for suppressing such a combustion instability. It is also notified, however, Zr powder would incur the acceleration of urethance forming reaction so as to make the pot life of the HTPB/AP propellant dough shorter. This paper reports that tetracycline (TC) is available to offset such a trouble in curing process brought about by Zr powder addition.