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Abstract  

AP/HTPB based composite propellants with additives such as ammonium oxalate (AO), mixture of ammonium oxalate and strontium carbonate (SC) was investigated by burning rate, TG-DTG and FTIR experiments. The results show that the burning rates of these propellants are decreased significantly. TG-DTG experiments indicate that decomposition temperatures of AP with these additives are increased. Furthermore, the activation energy of the decomposition reaction of AP is also increased in the presence of AO or AO/SC. These results show that AO or AO/SC restrains the decomposition of AP. The burning rates of these propellants are decreased. The burning rate temperature sensitivity of AP/HTPB based propellants is reduced significantly by the addition of AO or AO/SC. But the effect of AO is less than that of AO/SC. AO/SC is better effect to reduce temperature sensitivity and at the same time, to reduce pressure exponent. The reduced heat release at the burning surface of AP/HTPB/AO is responsible for the reduced temperature sensitivity. Synergetic action is probably produced between AO and SC within AP/HTPB based propellants in the pressure range tested. This synergetic effect causes the heat release to reduce and the burning surface temperature to increase. Moreover, it makes the net exothermal reaction of condensed phase become little dependent on T 0. Thus, the burning rate temperature sensitivity is reduced.

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Abstract  

The thermal decomposition of ammonium perchlorate (AP) is considered to be the first step in the combustion of AP-based composite propellants. In this report, the effect of the specific surface area of titanium oxide (TiO2) catalysts on the thermal decomposition characteristics of AP was examined with a series of thermal analysis experiments. It was clear that the thermal decomposition temperature of AP decreased when the specific surface area of TiO2 increased. It was also possible that TiO2 influences the frequency factor of AP decomposition because there was no observable effect on the activation energy.

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Abstract  

The chemical stability of a propellant and its influence on the ballistic properties during aging is a subject of interest. The effect of aging on ballistic properties, viz., ignition delay, burning rate, and heat of combustion for an aluminised ammonium perchlorate–hydroxyl-terminated polybutadiene (AP/HTPB) composite propellant during accelerated aging were investigated. Samples of composite propellants were aged at 60 and 70 °C at relative humidity of 50% in a climatic chamber. The propellant samples were tested with pressurized nitrogen gas environment for ignition delay measurement. Test results indicate that aging does not have any appreciable effect on ignition delay. The change in ignition delay time is less than 3% within the scatter of the data. Experiment results indicate that burn rate do affect with pressure but aging does not have much effect on burn rate. It was also observed that the burning rate at low pressures did not undergo significant changes during the aging period. The most significant of all the ballistic properties of this propellant is the burning rate exponent which increased by about 10% during the aging period.

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Abstract  

In a search for new storable high performance propellants for the European Space Agency (ESA), the solid oxidiser hydrazinium nitroformate (HNF) has been identified as a very promising ingredient for a new storable composite propellant. The purity and stability of HNF after production are very important indicators for the quality of HNF. In order to characterise HNF,many thermal analysis techniques as DSC and TG/DTA were performed to obtain more information about its stability and its (in)compatibility with other materials. Also some less familiar techniques such as the vacuum stability test and microcalorimetry have been performed. In relation to the safety, a relation between the friction and impact sensitivity and the physical-chemical properties is made.

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] investigated the effects of organo-metallic compounds of chromium- and cobalt-like chromium acetyl acetonate, cobalt oxide, cobalt stearate and cobalt 2-ethyl hexanoate on burning rate of HTPB–AN composite propellant. The propellants were prepared using the

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Adiabatic thermokinetics and process safety of pyrotechnic mixtures

Atom bomb, Chinese, and palm leaf crackers

Journal of Thermal Analysis and Calorimetry
Authors: Sridhar Vethathiri Pakkirisamy, Surianarayanan Mahadevan, Sivapirakasam Suthandathan Paramashivan, and Asit Baran Mandal

. J Pyrotech 21 : 52 . 3. Ramu S . Hazard evaluation techniques and hazard evaluation criteria for composite propellants and explosives . In: Vikram Sarabhai

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