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Studies on the High Performance Characteristics of an Aluminized Ammonium Perchlorate Composite Solid Propellant Based on Nitrile Butadiene Rubber

Sudhir Singh, Sidharth Raveendran, Dhirendra Kshirsagar R., Gupta Manoj, Chetan Bhongale

Central European Journal of Energetic Materials

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2021

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Vol. 18, no. 4

492--511

EN

n the present study, a high performance composite solid propellant formulation was prepared based on nitrile butadiene rubber (NBR) and dibutyl phthalate (DBP) plasticizer, which has a longer pot life and high density specific impulse. The developed cost effective novel binder system was prepared with readily available raw materials (NBR and DBP). The formulation of the composition was performed by varying the content of the NBR/DBP binder in the range of 14-20%. The rocket performance characteristics were determined theoretically using PROPEP and compared with those of an HTPB based propellant. The rheological, mechanical, physical, ballistic and thermal properties of the NBR/DBP propellant were studied and compared with literature data for similar compositions based on an HTPB/dioctyl adipate (DOA) binder. The yield stress was determined by spreadibilty measurements, and indicated the superiority of this binder based propellant over existing composite propellants. It was concluded that following decreasing the content of the NBR/DBP binder in the propellant from 20 to 14%: in the range 58.83-78.45 bar (5.883-7.845 MPa), the pressure index increased from 0.159 to 0.371, – at 68.64 bar (6.864 MPa), the burning rate increased from 4.10 to 6.54 mm/s, but the theoretical specific impulse value did not change significantly (258.0259.8 s), – the tensile strength and E-modulus increased from 6.03 to 9.88 (0.591-0.969) to and from 18.00 to 75.00 kgf/cm2 (1.765 to 7.355 MPa), respectively. Moreover, a DSC and TGA study indicated a lower decomposition temperature for the NBR/DBP propellant compared to the HTPB propellant. The NBR/DBP propellant exhibited a pot life more than double that of a conventional HTPB/ DOA based propellant.

2

Assessment of the Shelf Life of Composite Solid Propellants in Air and Nitrogen Atmospheres through Thermal Ageing

Keshavarz Mohammad Hossein, Hosseini Seyyed Hesamodin, Mehran Karimi

Central European Journal of Energetic Materials

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2021

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Vol. 18, no. 1

25--45

EN

This work introduces dynamic mechanical thermal analysis (DMTA) as an efficient method for the assessment of the shelf life of solid composite solid propellants in air and nitrogen atmospheres. The samples were aged at three temperatures 323.15, 333.15, and 343.15 K for 60, 120, and 180 days. The two different methods of Arrhenius and Berthelot were used to compare the effects of air and nitrogen atmospheres on the ageing of composite solid propellants. Damping (Tan δ) of composite solid propellants was used to determine the shelf life of the samples based on the loss of half of the physical property Tan δ (50% drop in damping). For the air atmosphere, the calculated activation energy for the degradation reactions of the samples was 86.26 kJ·mol–1. Both models, Arrhenius and Berthelot, confirmed that the shelf lives of the samples under the nitrogen atmosphere are more than four times those in an air atmosphere.

3

Badania nad modyfikacją składu heterogenicznego paliwa dla dwuzakresowego silnika rakietowego

Florczak B., Cholewiak A.

Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa

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2011

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Vol. 2, Nr 2 (4)

43-50

PL

W pracy przedstawiono wyniki z badań zmodyfikowanych ładunków napędowych dla dwuzakresowego silnika rakietowego. Modyfikacja polegała na optymalizacji składu heterogenicznego paliwa rakietowego na bazie nadchloranu amonu jako utleniacza i lepiszcza na bazie ciekłego kauczuku PBAN z dodatkiem Al. W rezultacie otrzymano paliwo z lepszymi parametrami energetycznymi w porównaniu do paliwa odniesienia.

EN

This paper presents the results of investigations of modified composite solid propellant charges for the dual made rocket motor. The modification has been done by selection of composition of the heterogeneous solid propellant made on the base of ammonium perchlorate as an oxidizer and the binder on the base of liquid rubber PBAN. As a result of modifications it was obtained the composite solid rocket propellant of better energetic and ballistic properties in comparison with the reference composite propellant.

4

The composite propellants with high-burning rate and low-pressure exponent

Florczak B., Lipiński M., Szymczak J.

Polish Journal of Applied Chemistry

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2003

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Vol. 47, nr 3

227-230

EN

The ballistic properties of composite propellants can be manipulated by various methods. Incorporating fine AP and ferrocene particles or liquid n-butylferrocene increase the burning rate. The calorific value of the propellants were measured with the adiabatic bomb IKA calorimeter system C 4000. The burning rate of the propellants were measured with a small rocket motor (SRM) for measuring burning rate testing system. The burning rate of the propellant was found to increase with the increasing ferrocene and/or n-butylferrocene content of the propellant. The pressure exponent of the propellant has the least value for the propellant content SOE < 0.1.

PL

Balistyczne właściwości heterogenicznych stałych paliw rakietowych mogą być modyfikowane w różny sposób. Wprowadzając drobny nadchloran amonu (NA) i ferrocen lub ciekły n-butyloferrocen zwiększono szybkość spalania. Kaloryczność paliw określono przy pomocy bomby kalorymetrycznej w kalorymetrze IKA C 4000. Szybkość spalania paliw określano poprzez pomiary w układzie z małym silnikiem rakietowym. Szybkość spalania paliwa wzrasta ze wzrostem zawartości ferrocenu i/lub n-butyloferrocenu w paliwie. Wykładnik potęgowy był najmniejszy dla paliwa zawierającego SOE i był < 0,1.