Burning Characteristics of AP/HTPB Composite Propellants Prepared with Fine Porous or Fine Hollow Ammonium Perchlorate

Abstract

Fine porous and hollow ammonium perchlorate (AP) particles were prepared by the spray‐drying method. Propellants prepared with porous or hollow AP were found to have bubble contamination. The bubble in the propellant appeared inside the porous and hollow AP particles because the voids in porous and hollow AP cannot be completely filled with HTPB. The relationship between the burning rate and the weight mean diameter, Dw, and the specific surface area, Sw, is divided into two regions. The burning rate was almost constant above the critical Dw and increased with decreasing Dw below that. The burning rate was almost constant below the critical Sw and increased with increasing Sw above that. These critical points did not depend on the voids in the AP particles. The burning rate of the propellant prepared with spherical AP was dependent on Dw and Sw. The burning rates of the propellants prepared with porous or hollow AP were not associated with Dw or Sw alone and were greater than that of the propellant prepared with spherical AP at a constant Dw or Sw. The voids in porous and hollow AP particles thus had a positive effect on the burning rate.

Efficient Sensitivity Reducing and Hygroscopicity Preventing of Ultra‐Fine Ammonium Perchlorate for High Burning‐Rate Propellants

“…In view of the high sensitivity caused by UF-AP, desensitization techniques have been investigated largely. Kohga synthesized fine porous or hollow AP by spray-drying method [14], in this case, the void structure inside the porous AP particles exhibited positive effects on the burning rate, nevertheless, the loading density would be in a low level. Nandagopal developed a precipitation technique to coat AP using a copolymer of hexafluoropropylene and vinylidene fluoride [15], resulting the increased burning rate, tensile strength and thermal stability after coating.…”

Study on Burning and Thermal Decomposition Properties of HTPB Propellant Containing Synthesized Micro‐nano Ferric Perfluorooctanoate

“…According to the published works, there's an intrinsic relationship between burning properties and the thermal decomposition of ammonium perchlorate (AP). It has been approved that the burning rate of AP-based composite solid propellant increases as the decomposition temperature of AP decreases [3][4][5][6]. In the past decades, the application of metal oxides and metal salts as catalysts was popularized for obtaining better decomposition properties of AP and combustion efficiency of AP-based composite solid propellant.…”

“…In our previous studies [21], ferric perfluorooctanoate Fe(PFO) 3 was prepared as a good catalyzer for the decomposition of AP. It was proved that Fe(PFO) 3 could decrease the activation energy of Fe(PFO) 3 /AP mixture and increase total heat release of AP significantly.…”

“…Based on this result, Fe(PFO) 3 is expected to be a promising additive which has a good effect on the burning properties of AP-based composite solid propellant. However, the influence of Fe(PFO) 3 on burning and thermal decomposition properties of composite solid propellant as well as the reaction mechanism between Fe(PFO) 3 and aluminum are still not clear. Thereby, it's necessary to study the effects of Fe(PFO) 3 on AP-based composite solid propellant.…”

Preparation and characterization of superfine ammonium perchlorate (AP) crystals through ceramic membrane anti-solvent crystallization

“…During the past two decades, considerable attention has been paid to the preparation of superfine AP crystal to achieve better combustion behavior of the solid propellant [1][2][3][4][5][6]. Among those efforts, typical methods for superfine AP preparation include jet milling [2], supercritical anti-solvent crystallization (SASC) [3], salting-out crystallization (SOC) [4,5] and liquid anti-solvent crystallization (LASC) [6].…”