Ammonium nitrate , thermal

However, Feick and Hainer [18] consider most of the above figures of the energy of activation are not very accurate as in the period prior to explosion a considerable quantity of ammonium nitrate is evaporated. The authors suggest the following equations for ammonium nitrate thermal decomposition ... 

Generation of radicals by redox reactions has also been applied for synthesizing block copolymers. As was mentioned in Section II. D. (see Scheme 23), Ce(IV) is able to form radical sites in hydroxyl-terminated compounds. Thus, Erim et al. [116] produced a hydroxyl-terminated poly(acrylamid) by thermal polymerization using 4,4-azobis(4-cyano pentanol). The polymer formed was in a second step treated with ceric (IV) ammonium nitrate, hence generating oxygen centered radicals capable of starting a second free radical polymeriza-... 

Brown A.C. McLaren, On the Mechanism of the Thermal Transformations in Solid Ammonium Nitrate , ProcRoySoc 266A, 329—43 (1962) 27) Anon, Department of the Army... 

Dinitrogen oxide, N20, gas was generated from the thermal decomposition of ammonium nitrate and collected over water. The wet gas occupied 126 mL at 21°C when the atmospheric pressure was 755 Torr. What volume would the same amount of dry dinitrogen oxide have occupied if collected at 755 Torr and 21°C The vapor pressure of water is... 

According to an O.S. amendment sheet, the procedure as described [1] is dangerous because the reaction mixture (dicyanodiamide and ammonium nitrate) is similar in composition to commercial blasting explosives. This probably also applies to similar earlier preparations [2]. An earlier procedure which involved heating ammonium thiocyanate, lead nitrate and ammonia demolished a 50 bar autoclave [3], TGA and DTA studies show that air is not involved in the thermal decomposition [4], Explosive properties of the nitrate are detailed [5], An improved process involves catalytic conversion at 90-200°C of a molten mixture of urea and ammonium nitrate to give 92% conversion (on urea) of guanidinium nitrate, recovered by crystallisation. Hazards of alternative processes are listed [6],... 

The explosion efficiency is one of the major problems in the equivalency method. The explosion efficiency is used to adjust the estimate for a number of factors, including incomplete mixing with air of the combustible material and incomplete conversion of the thermal energy to mechanical energy. The explosion efficiency is empirical, with most flammable cloud estimates varying between 1 % and 10%, as reported by a number of sources. Others have reported 5%, 10%, and 15% for flammable clouds of propane, diethyl ether, and acetylene, respectively. Explosion efficiencies can also be defined for solid materials, such as ammonium nitrate. 

Self-sustaining thermal decomposition of NPK fertilisers is apparently possible if crystalline potassium nitrate is present from a exchange reaction of ammonium nitrate [1], Almost pure fertiliser grades of ammonium nitrate are legally restricted in some countries because of its instability [2],... 

Treatment of the ammonium salt of 3,5-dinitro-1,2,4-triazole (113) with hydrazine hydrate leads to selective reduction of one of the nitro groups to yield 3-amino-5-nitro-1,2,4-triazole (ANTA) (114), a high performance explosive (calculated VOD 8460 m/s) possessing thermal stability (m.p. 238 °C) and an extremely low sensitivity to impact. ANTA (114) is also synthesized from the nitration of 3-acetyl-l,2,4-triazole with anhydrous nitric acid in acetic anhydride at subambient temperature followed by hydrolysis of the acetyl functionality. The ammonium salt of 3,5-dinitro-l,2,4-triazole (113) is itself a useful explosive which forms a eutectic with ammonium nitrate. ... 

Ammonium nitrate (AN) is a crystalline oxidizer that produces an oxidizer-rich gas when thermally decomposed according to ... 

Nitrous Oxide Nitrous oxide (1.1.11) is synthesized either by the thermal decomposition of ammonium nitrate, or by the oxidation of sulfamic acid by nitric acid [9-11]. 

Thermal decomposition of symmetrical hydrazines (212a-d) according to equation 30 resulted in excellent yields of hindered esters (231a-d). The hydrazines leading to the esters were generated as intermediates by the oxidation of Af-alkoxyamides using ceric ammonium nitrate or Ni02.H20 (Scheme 31). 

Thermal dissociation yields lanthanum oxide, La203. Its reactions in aqueous solutions are those of La ion. It forms double salts with magnesium, calcium and ammonium nitrates and many other salts when mixed in stoi-chiometic amounts. Such double salts are obtained from solution mixtures on crystalhzation and may vary in their compositions. 

The most important attributes of this invention are high impulse performance coupled with high exit temperature on primary combustion and favorable boron species in the primary motor exhaust. The system is also insensitive to impact and possesses excellent thermal stability at elevated temperatures. Additionally, the system is readily castable since the addition of solid oxidizers is not required. Further, high flexibility in the ballistic properties of the gas generator can be achieved by the addition of solid oxidizers such as ammonium nitrate, ammonium perchlorate, hydroxylammonium perchlorate, potassium perchlorate, lithium perchlorate, calcium nitrate, barium perchlorate, RDX, HMX etc. The oxidizers are preferably powdered to a particle size of about 10 to 350 microns [13]. 

Nitric oxide is commercially produced by the catalytic oxidation of ammonia using a platinum catalyst 4NH3(g) + 50 —> 4NO(g) + 6H20(g). Nitrous oxide is produced by the thermal decomposition of ammonium nitrate at approximately 240°C NH4N03(g) —> N O + 2H . ... 

It is worth emphasizing that the reaction scheme above is able to explain not only the stoichiometry of the fast SCR reaction, and specifically the optimal equimolar NO to N02 feed ratio, but also the selectivity to all of the observed products, namely N2, NH4NO3 and N20, which derives from thermal decomposition of ammonium nitrate (Ciardelli et al., 2004b, 2007a Nova et al., 2006b) furthermore it is in agreement with the observed kinetics of the fast SCR reactions, which at low temperature is limited by the rate of the reaction between nitrate and NO. 

The thermal expansions in c.c. per gram of some of the different forms of ammonium nitrate have been measured by M. Bellati and R. Romanese, U. Behn, and P. W. Bridgman. U. Behn measured the coeff. of expansion of the solid between —60° and 100° and found ... 

Observe the thermal phenomena occurring when 0.1 mol of the following salts is dissolved in 50 ml of water ammonium nitrate, anhydrous sodium sulphate, and sodium sulphate decahydrate (Glauber salt). For this purpose, pour 50 ml of water into a 100-ml beaker, measure its temperature, and, after pouring in the relevant amount of a salt, see how the temperature changes. Explain what occurs. 

Another constituent of perchlorate explosives, ammonium perchlorate, unlike ammonium chlorate, is stable. It is also dissimilar to potassium perchlorate in being an explosive in the pure state, like ammonium nitrate. The greater specific gravity of ammonium perchlorate gives to explosives with which it is mixed a greater power than that of similar ammonium nitrate explosives. The former are also more sensitive than chlorate explosives to friction and impact and to thermal ignition. 

Incompatibility of the second type appears as an unexpected increase in sensi-tivenes or decrease in thermal stability, and may be caused by any of the foregoing phenomena. Rogers found that zinc reacts readily with ammonium nitrate. He also found that adding 20% urea to RDX reduces the thermal stability of the latter. 

Fig. 126. Thermal layer model of combustion of solid composite propellant with ammonium nitrate, according to Chaiken [2] R—redox reaction flame zone (temperature 7f), u—gas velocity, S—thickness of the thermal layer, T —surface temperature of oxidizer particle, ro—radius of oxidizer particle.

Allylic carboxylation. Diethyl oxomalonate (1) undergoes a thermal ene reaction with mono-, di-, and trisubstituted alkenes at 145 180°. The reaction is also subject to catalysis with Lewis acids, which can lead to a different ene product. The products are a-hydroxymalonic esters. The corresponding malonic acids are converted to carboxylic acids by bisdecarboxylation with NaI04 and a trace of pyridine- or with ceric ammonium nitrate (CAN). Diethyl oxomalonate then functions as an cnophilic equivalent of C02. 

A negative thermal effect accompanies the transformations of the ammonium nitrate crystal form with rising temperature, whereas during cooling the process is of course exothermic (Table 110). 

Crystalline form of ammonium nitrate Temperature °C Change of volume cm3/g Thermal effect cal/g... 

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