Kaushal Kishore

• wigan and leigh

Equations for solid-state decompositions which are controlled by the phase-boundary movement and nucleation have been examined using ammonium perchlorate/polystyrene propellant decomposition at 503 K and 533 K. It was found that 3 different equations governed by the nucleation process show a good fit of data at these temperatures. However, the best...

A new cross-linking agent for carboxyl-terminated polybutadlene, 1,3,5-tris[(2-methylaziridinyl-1)methyl]benzene, was prepared from 2-methylaziridine and 1,3,5-tris(bromomethyl)benzene.

During the thermal decomposition of orthorhombic ammonium perchlorate (AP) at 230°C, where the decomposition is only up to 30 wt %, there is an accumulation in the solid of acids, the concentration of which increases up to 15% decomposition, after which it decreases till it reaches the original value. Similar observations have been made in the poly...

An electric field (100 V/cm at 230°C and 150°C) has been applied to ammonium perchlorate (AP)/polystyrene (PS) propellant mixtures in order to understand the low temperature decomposition behavior of the propellant. The charge-carrying species is anionic in nature at 230°C, which could be ClO4−, but is cationic at 150°C, which could be either NH4+...

The calorimetric values of composite solid propellant based on polystyrene, polyphenolformaldehyde, poly(vinyl chloride) and carboxy-terminated polybutadiene were determined using combustion calorimetry in order to assess the uncertainities in their measurements. The dependence of the calorimetric values on various propellant composition was obtain...

Studies on Thermal decomposition of ammonium perchlorarte(AP)- polystyrene(PS) propellant and burning rate of PS/AP propellant have been carried out as a function of oxidizer particle size. Thermal decomposition of AP and AP/PS propellant as function of AP particle size shows a maximum rate around 100 micro particle size which has been explained on...

An attempt has been made to bring the literature on polymeric peroxides together from all angles in order to present a comprehensive picture about them. Both polyperoxides, where the peroxide group has been attached to the main chain, and polymeric hydroperoxides, where the peroxide group is present as a side chain, have been considered. Various as...

Reproducibility of the output signal in Differential Scanning Calorimeter has been examined in detail. The ordinate calibration factor has been found to diminish at higher temperatures. Calibration factor for enthalpy output has also been evaluated. A procedure for calibrating the area by the proper selection of the base-line for both scanning and...

Transition metal oxides (TMO) are known to promote the thermal decomposition (TD) of ammonium perchlorate (AP), deflagration of AP, AP-binder sandwich burning, and the combustion of AP-based composite solid propellants. In order to understand how these catalysts affect the combustion of propellants, two systems based upon polystyrene (PS) and carbo...

STUDIES on potassium perchlorate/polystyrene (KP/PS) propellant systems have been carried out by using such techniques as thermogravimetry (TG), differential thermal analysis (DTA), and mass spectrometry (MS). It has been found that the thermal decomposition (TD) behavior of the KP/PS propellant is similar to that of the AP/PS propellant studied ea...

The effect of transition metal oxides (Fe2O3, MnO2, Ni2O3 and Co2O3) on polystyrene/ammonium perchlorate propellant systems has been examined. The mechanism of action of the oxides in increasing the burning rate was examined by studying the effect of the oxides on the thermal decomposition and combustion of the oxidizer and the propellant. It has b...

Vacuum pyrolysis of ammonium perchlorate (AP) and ammonium perchlorate/polystyrene (PS) propellant has been studied by differential thermal analysis (DTA) in order to observe the effect of transition metal oxides on sublimation. Sublimation and decomposition being competitive processes, their proportions depend on the pressure of the pyrolysis cham...

Polystyrene peroxide has been synthesized and its decomposition has been studied by thermogravimetry and differential thermal analysis. Polystyrene peroxide has been found to decompose exothermically at about 110°C. The activation energy for the decomposition was estimated to be 30 kcal/mole both by the Jacobs and Kureishy method and by fitting the...

Summary A correlation has been established between the heat of depolymerization (?H) of vinyl polymers for going from solid polymer state to gaseous monomer state and the activation energy (E) of degradation. On this basis it has been shown that the rate controlling step in the degradation lies in the initiation step. Attempt has been made to corre...

Transition metal oxides like Fe//2O//3, CuO, MnO//2, CuCr//2O//4, etc. , form a very popular group of catalysts for burning rate modification of composite solid propellants. In this literature review, a comprehensive picture is drawn of the mechanism of the action of these catalysts.

Accelerated ageing studies for three composite propellant formulations, namely polystyrene (PS)/ ammonium perchlorate (AP), polymethylmethacrylate (PMMA)/AP and poly phenol formaldehyde (PPF)/AP have been carried out in the temperature range of 55-125°C. Measurements of the ultimate compression strength (Uc) and isothermal decomposition rate (TD ra...

A novel method of detecting the charge-carrying species in inorganic decomposable salts is described. In ammonium perchlorate it is observed that the charge-carrying species at temperatures 150 and 230°C are oppositely charged; i.e., they are negatively charged (ClO−4 ions) at 230°C and positively charged (H+ or NH+4) at 150°C.

THE importance of aging studies arises from the assessment of the safe life of the propellant. The objective of the present review is to give a comprehensive picture of the up-to-date knowledge available in the literature on the subject, covering both double-base and composite solid propellants. The present review covers the following topics: 1) fa...

Ageing behaviour, leading to ballistic changes, has been studied as a function of oxidizer loading in polystyrene/ammonium perchlorate solid-propellants. The ageing studies were carried out at 100 °C in air. Change in burning rate decreased as the oxidizer loading increased from 75 to 80%. The change in thermal decomposition rates both at 230 and 2...

Chromium trioxide has been found to be powerful oxidising agent for supporting the combustion of many organic fuels like alcohols, aldehydes and ketones. Ignitability of butanols follows the order, n-butanol> sec-butanol>tertbutanol. Chromium, trioxide supports combustion by supplying the necessary oxygen by its own dissociation. During the combust...

The paper describes the effect of catalyst concentration on the burning rates of solid propellants containing ammonium perchlorate and polystyrene at ambient pressure and temperature (25 degree C in air).

Thermal decomposition of powdered ammonium perchlorate, catalysed by manganese dioxide (MnO2), has been studied in the low concentration ranges of the catalyst. MnO2 sensitises the thermal decomposition of ammonium perchlorate. The activation energy estimations of catalysed ammonium perchlorate show that the value is about 30 kcal/mol throughout th...

Ageing behaviour of polystyrene (PS)/ammonium perchlorate (AP) propellent leading to ballistic changes has been studied. It follows a zero-order kinetic law. Ageing behaviour leading to change in burning rate ( ) in the temperature range of 60–200 ° C was found to remain the same. The dependence of the change of the average thermal decomposition (T...

Abstract is not available.

The mechanism of combustion of composite-solid propellants has been studied. Results show that thermal decomposition of the propellant takes place in the condensed-phase during the steady-state burning process; the thin-layer chromatographic analysis has given a positive proof to this effect. The intermediate species formed during the decomposition...

The effects of pretreatments on the sublimation of pure ammonium perchlorate (AP) were studied by differential thermal analysis. The addition of inorganic salts (doping), or preheating, lead to desensitisation of the sublimation process, whereas it was sensitised by precompression. Sublimation increased with decrease in the particle size of the AP...

The role of thermal decomposition of the binder and the oxidiser in the thermal decomposition, ageing and combustion of composite solid-propellants has been investigated. The present study shows that the burning rate and ageing of polystyrene and ammonium perchlorate propellant are related to the thermal decomposition of the propellant itself and a...

The importance of the study of thermal degradation of polymeric fuels arises from their role in the combustion of solid propellants. Estimation of the condensed-phase heat release during combustion can be facilitated by the knowledge of the enthalpy change associated with the polymer degradation process. Differential scanning calorimetry has been u...

To obtain a deeper insight into the thermal decomposition process of ammonium perchlorate (AP)-based composite propellants, a quantitative analysis of the thermal changes associated with the binder, oxidizer, and the propellant was conducted. The primary objectives were the enthalpy and kinetic estimations from the Differential Scanning Calorimetri...

Hybrid combustion of an aluminized polystyrene/oxygen system has been investigated. The mass consumption rate of the fuel is found to be proportional to the square root of the mass consumption rate of the oxidizer. The regression rate depends on time, as was found to be the case for an unmetallized propellant. The role of radiative heat transfer to...

Differential scanning calorimetric studies on ammonium perchlorate have been carried out. The enthalpy values for the phase transition endotherm and the two exotherms have been reported in the present communication. A new method has been developed for the estimation of kinetic parameters from DSC the mograms. The values for activation energy as cal...

An investigation has been made with the objective to seek a correlation between the burning rate and the thermal decomposition of the propellant and oxidizer and, second, to see whether the burning rate increases when the oxidizer is doped with potassium chromate. It has been found that burning rate depends upon the thermal decomposition behavior o...

The condensed phase reactions occurring in the combustion of solid propellants, observed in differential scanning calorimetric (DSC) studies and in mass spectrometric (MS) studies have been examined. A difference has been found between the results of these studies and the cause of this difference has been investigated.

Decomposition of solid propellants, relevant in combustion processes, has been studied by differential scanning calorimetry (DSC). Enthalpy changes for decomposition of the polymers [polystyrene (PS) and styrene-oxygen copolymer (co-polymer)], ammonium perchlorate (AP) and the corresponding propellants have been estimated from DSC thermograms. Ener...

The hybrid combustion of polystyrene and oxygene styrene copolymer has been studied. The linear regression rate r and total mass flow of fuel m//f have been measured at different oxygen flow rates and at different times intervals. It is found that the regression rate decreases with time. Detailed analysis of the data shows that it is due to radiati...

A comparative study of combustion of polystyrene and oxygen-styrene copolymer/ammonium perchlorate composite propellants has been made in order to investigate the role of peroxide-linkage in the latter, and to study the role of surface reactions in combustion.

The chemistry of elastomers, including high energy binders, currently used as rocket fuels is reviewed. The processing of polymers and propellants, including plasticization and curing, is discussed. The mechanical and ballistic properties of propellants and their dependence on propellant formulations are examined.