Shape and size improvement of the hexogen (RDX) and octogen (HMX) particles and their effect on the processibility and hardness of the propellants have been carried out with polyurethane-based HTPB (PU-HTPB) coating and washing treatment. Both RDX and HMX were coated by the solution coating method. A total of 200 grams of RDX and HMX were mixed with a solution of Hydroxyl-Terminated Polybutadiene/toluene diisocyanate (HTPB/TDI) with a weight ratio of 14/1 and a concentration of 2 mL/200mL of ethyl acetate, stirred for 20 minutes, filtered, and dried in an oven for a week at 60oC. RDX and HMX were treated with no washing, one-time washing, and three-times washing with alcohol. RDX and HMX coatings can increase particle size. A 20% increase in particle size improves the propellant slurry’s viscosity by 13.824%. Washing coated RDX or HMX can improve the particle’s shape. One-time washing changes the roundness up to 8.157%, deflating the surface area up to 57.064%, thereby reducing the viscosity of the propellant slurry by 13.824%. Moreover, increasing the washing up to three times decreases the roundness and viscosity of the propellant slurry by 23.521%. In general, the propellant slurry can still be processed using the vacuum casting method, and the slurry viscosity is still below 20,000 Poise. The average viscosity of the HMX propellant slurry is higher than that of RDX. Based on the optimization results, optimal RDX and HMX are obtained by using RDX coating with PU-HTPB and one-time washing so that there is a slight change in particle size (less than 5%), giving better roundness, resulting in a decrease at the end of mixing (EOM) viscosity of 28.127%, and better propellant processability. The hardness analysis of cured propellant supports this statement. The hardness characterization shows a similar trend to the viscosity of the slurry propellant.

1.
Wei An
C.
,
Li
,
F.S.
,
Song
,
X.L.
,
Wang
,
Y.
,
Guo
,
X.D.
Surface Coating of RDX with a Composite of TNT and an Energetic-Polymer and its Safety Investigation
.
Propellants, Explosives, Pyrotechnics.
2009
;
34
:
400
405
. doi:
2.
Wibowo
,
H.
,
Sitompul
,
H.
,
Budi
,
R.
, et al
Hexogen Coating Kinetics with Polyurethane-Based Hydroxyl-Terminated Polybutadiene (HTPB) Using Infrared Spectroscopy
.
Polymers (Basel).
2022
;
14
:
1184
. doi:
3.
DeLuca
,
L.
,
Cozzi
,
F.
,
Germiniasi
,
G.
,
Ley
,
I.
,
Zenin
,
A.
Combustion mechanism of an RDX-based composite propellant
.
Combustion and Flame-COMBUST FLAME.
1999
;
118
:
248
261
. doi:
4.
An
,
C.
,
Wang
,
J.
,
Xu
,
W.
,
Li
,
F.
Preparation and Properties of HMX Coated with a Composite of TNT/Energetic Material
.
Propellants, Explosives, Pyrotechnics.
2010
;
35
(
4
):
365
372
. doi:
5.
Suresh Babu
K v
,
Kanaka Raju
,
P.
,
Thomas
,
C.R.
,
Syed Hamed
,
A.
,
Ninan
,
K.N.
Studies on composite solid propellant with tri-modal ammonium perchlorate containing an ultrafine fraction
.
Defence Technology.
2017
;
13
(
4
):
239
245
. doi:
6.
Restasari
,
A.
,
Abdillah
,
L.H.
,
Ardianingsih
,
R.
, et al
Thixotropic Behavior in Defining Particle Packing Density of Highly Filled AP/HTPB-Based Propellant
.
Symmetry (Basel).
2021
;
13
(
10
). doi:
7.
Ashish
,
J.
,
Swaroop
,
G.
,
Balasubramanian
,
K.
Chapter 8-Effect of Ammonium Perchlorate Particle Size on Flow, Ballistic, and Mechanical Properties of Composite Propellant. In:
Yan
,
Q.L.
,
He
,
G.Q.
,
Liu
,
P.J.
,
Gozin
M
, eds.
Nanomaterials in Rocket Propulsion Systems
.
Micro and Nano Technologies. Elsevier
;
2019
:
299
362
. doi:
8.
Mezroua
,
A.
,
Khimeche
,
K.
,
Lefebvre
,
M.H.
,
Benziane
,
M.
,
Trache
,
D.
The influence of porosity of ammonium perchlorate (AP) on the thermomechanical and thermal properties of the AP/polyvinylchloride (PVC) composite propellants
.
J Therm Anal Calorim.
2014
;
116
(
1
):
279
286
. doi:
9.
Beckstead
,
M.
,
Derr
,
R.
,
Price
,
C.
A Model of Composite Solid-Propellant Combustion Based on Multiple Flames
.
AIAA Journal.
1970
;
8
:
2200
2207
. doi:
10.
Kanagaraj
,
G.
,
Chakravarthy
,
S.
,
Kandasamy
,
J.
, et al
Combustion behaviour of composite sandwich propellants containing RDX
.
Proceedings of the Combustion Institute.
2020
;
38
. doi:
11.
Spyckerelle
,
C.
,
Eck
,
G.
,
Sjöberg
,
P.
,
Amnéus
,
A.M.
Reduced sensitivity RDX obtained from Bachmann RDX
.
Propellants, Explosives, Pyrotechnics.
2008
;
33
:
14
19
. doi:
12.
Xiao
,
J.
,
Zhao
,
L.
,
Zhu
,
W.
, et al
Molecular dynamics study on the relationships of modeling, structural and energy properties with sensitivity for RDX-based PBXs
.
Sci China Chem.
2012
;
55
(
12
):
2587
2594
. doi:
13.
Sitompul
,
H.R.
,
Wibowo
,
H.B.
,
Abdillah
,
L.H.
, et al
Integrated Quality Analysis Method of Aluminum for Composite Propellant Production
.
Jurnal Teknologi Dirgantara.
2021
;
19
(
2
):
177
192
. doi:
14.
Kornilov
,
A.
,
Safonov
,
I.
An Overview of Watershed Algorithm Implementations in Open Source Libraries
.
J Imaging.
2018
;
4
(
10
). doi:
15.
Mohazzab
,
P. Archimedes
Principle Revisited
.
Journal of Applied Mathematics and Physics.
2017
;
05
(
04
). doi:
16.
Zdilla
,
M.J.
,
Hatfield
,
S.A.
,
McLean
,
K.A.
,
Cyrus
,
L.M.
,
Laslo
,
J.M.
,
Lambert
,
H.W.
Circularity, Solidity, Axes of a Best Fit Ellipse, Aspect Ratio, and Roundness of the Foramen Ovale
.
Journal of Craniofacial Surgery.
2016
;
27
(
1
):
222
228
. doi:
17.
Betoret
,
E.
,
Betoret
,
N.
,
Carbonell
J v.
,
Fito
,
P.
Effects of pressure homogenization on particle size and the functional properties of citrus juices
.
J Food Eng.
2009
;
92
(
1
):
18
23
. doi:
18.
Argade
,
P.S.
,
Magar
,
D.D.
,
Saudagar
,
R.B.
Solid Dispersion: Solubility Enhancement Technique for poorly water soluble Drugs
.
Journal of Advanced Pharmacy Education & Research.
2013
;
3
(
4
):
427
439
. www.japer.in
19.
Delmas
,
H.
,
Barthe
,
L.
Ultrasonic mixing, homogenization, and emulsification in food processing and other applications. In:
Power Ultrasonics
.
Elsevier
;
2015
:
757
791
. doi:
20.
Santana
,
R.C.
,
Perrechil
,
F.A.
,
Cunha
,
R.L.
High-and Low-Energy Emulsifications for Food Applications: A Focus on Process Parameters
.
Food Engineering Reviews.
2013
;
5
(
2
):
107
122
. doi:
21.
Hoffman
,
D.M.
Density Distributions of Cyclotrimethylenetrinitramines (RDX)
. In: ;
2002
. https://www.osti.gov/biblio/15005557
22.
Yang
,
W.
,
Li
,
Y.
,
Ying
,
S.
Fabrication, Thermoanalysis, and Performance Evaluation Studies on RDX-based Microcellular Combustible Objects
.
Propellants, Explosives, Pyrotechnics.
2014
;
39
(
4
):
568
573
. doi:
23.
Restasari
,
A.
,
Abdillah
,
L.H.
,
Ardianingsih
,
R.
, et al
Particle packing models to determine time-dependent slip flow properties of highly filled polyurethane-based propellant
.
Journal of Rubber Research.
Published online July 11,
2022
. doi:
24.
Thiyyarkandy
,
B.
,
Jain
,
M.
,
Dombe
,
G.S.
,
Mehilal
,
Singh
, P.P.,
Bhattacharya
,
B.
Numerical studies on flow behavior of composite propellant slurry during vacuum casting
.
Journal of Aerospace Technology and Management.
2012
;
4
(
2
):
197
203
. doi:
25.
Wibowo
,
H.B.
,
Luthfia
,
H.A.
,
Budiman
,
Y.
, et al
TDI addition sequence in the propellant production process and parameters for scale down/up
. In: ;
2021
:
040007
. doi:
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