THE EFFECTS OF CHROMIUM COMPOUNDS ON PVA-COATED AN AND GAP BINDER PYROLYSIS, AND PVA-COATED AN GAP PROPELLANT COMBUSTION/

Pyrolysis characteristics of a mixture consisting of PVA-coated AN and chromium compounds as burning modifiers have been investigated in det ail at pressures ranging from 0.1 to 5 MPa by means of DTA, DSC and TG . It has been found that the encapsulation of AN by PVA hardly affects pyrolysis characteristics of AN alone and AN with chromium compounds as burning accelerator. Chromium compounds enhance the pyrolysis react ion of AN by the following order; (NH4)(2)Cr2O7 greater than or equal to (NH4)(2)CrO4 > Cr2O3, but they do not affect the pyrolysis of GAP f uel-binder. The effects of chromium compounds on the burning rate of P VA-coated AN/GAP propellant have been examined. They enhance the burni ng rate of the propellant at pressure up to 7 MPa. Chromium oxide and ammonium dichromate would have a significant effect on the gas phase r eaction and on both condensed-phase and gas phase reaction, respective ly. GAP is also considered to promote the condensed-phase reaction dur ing combustion. (C) 1998 Elsevier Science Ltd. All rights reserved.