Thennal decomposition

This experimental investigation focuses on the preparation of polycrystalline magnesium oxide nanorods via capillary-driven infiltration of a precursor solution into the cylindrical pores of a track-etched polycarbonate membrane followed by thennal decomposition procedure. The nanomaterial was fully characterized by SEM, EDX,... 

Two-line ferrihydrite, for use as a catalyst, can also be synthesized by thermal decomposition of iron penta carbonyl, Fe(CO)5, in a stream of moist air at 500°C (Kosowski, 1993 Zhao et al.l993). It is a free flowing, reddish brown powder with a much lower bulk density than freeze-dried ferrihydrite prepared as above, probably because of much weaker aggregation. Small changes in the reaction conditions (water content of the air, duration of heating) may induce hematite formation. An analogous recipe involved slow thennal decomposition of trinuclear aceto-hy-droxy Fe "-nitrate for 20-40 hr in air in an attempt to simulate the red pigment on the Martian surface (Morris et al. 1991). 

Thennal decomposition of cyclonite was investigated by numerous authors (also Vol. Ill, p. 83) [110-115]. Maksimov [111] described several experiments of decomposition of cyclonite and octogene as solid substances and in solution. The energy of activation was calculated as E = 52.0 kcal/mol, log) o 19.1. 

Kabanov, A. A. eta ., Russ. Chem. Rev., 1975, 44, 538-551 Application of electric fields to various explosive heavy metal derivatives (silver oxalate, barium, copper, lead, silver or thallium azides, or silver acetylide) accelerates the rate of thennal decomposition. Possible mechanisms are discussed. 

Thennal decomposition of ammonium diuranate at 600°C in H2. Ground and water-washed. 

Cubbon RCP (1969) The kinetics of thennal decomposition of organic peroxides. In Porter G (ed) Progress in reaction kinetics, vol.5. Pergamon, Laporte Ind.Luton, p 31... 

Alternatively, thennal decomposition or disproportionation can yield the lower halide ... 

The proposed polymerization mechanism is shown in Scheme 9.12. Thennal decomposition of the hexasubstituted ethane derivative yields hindered tertiary radicals that can initiate polymerization or combine with propagating species (primary radical termination) to form an oligomeric macroinitiator. I he addition of the diphenylalkyl radicaLs to monomer is slow e.g. k for 34 is reported a.s 10 M s at 80 0 ) and the polymeri7.ation is characterized by an inhibition period during which the initiator is consumed and an oligomeric macroinitiator is formed. The bond to the CHt formed by addition to monomer is comparatively thermally stable. 

Darnez and co-workers [193, 194] revealed the formation of free radicals from secondary nitramines as the result of 7 and ulira-violct radiation. Recently Dubovitskii and Korsunskii [4] have review ed nitramines from the point of view of the kinetic value of their thennal decomposition anti came to the conclusion of free radical-chain reaction of breaking the N. NO, bond. Also a monograph on octogen has appeared [5]. 

Thennal decomposition of aliphatic-aromatic polyamides was mainly investigated by Py-MS. It was found in an early study that the thermal degradation of copolyamides formed from aliphatic and aromatic amino acids occurred almost exclusively through the bond scission in the aliphatic moieties. It was shown by Py-EIMS that thermal degradation of copolyamides of p-aminobenzoic acid and some aliphatic amino acids yielded poly-p-aminobenzoic acid via the elimination of lactams ... 

Thennal decomposition of spent sulfuric acids to give sulfur dioxide is achieved in a furnace at temperatures around 1,000 °C. Spent acids come from processes where H2SO4 or oleum is used as a catalyst (alkylation, nitration, sulfonation, etc.) or from other processes where H2SO4 is used to clean, dry, and remove water. 

Scheme 1 Thennal decomposition of polyacrylate a in absence and b in presence of novolac...

Fig. 22. Thennal decomposition of La2(C03>3 - SHjO in different atmospheres and the formation of La2(>2C03 (Head and Holley, 1964).

It is common practice to limit the temperature of the slurry oil to a maximum of 700 degrees F to minimize thennal decomposition in the section of the tower below the first product draw tray. 

The extent of oxidation within a UHMWPE hip or knee component, at a certain depth beneath the surface, depends on the actual concentration of alkyl radicals and on the amount of available oxygen [37 2]. The actual concentration of alkyl radicals is a function of both the dispensed dose rate and the temperature of the sterilization room because further radicals can result from thennal decomposition of hydroperoxides. 

Fatty oils on heating may undergo thennal decomposition. Evolution of vapours of decomposition products and traces of free fatty acids present in the oils gives rise to freaky flashes. Flash points of fatty oils vary between 300-500 F. 

The main processes which can be studied are loss of water of crystallisation, thennal decomposition, oxidation and desorption. Qualitatively, the identity of a sample can be confirmed by comparing its thermogram with that of a standard sample. In some decomposition reactions, an intermediate can be established from an inflection in the thermogram e.g. 2CUO.SO3 in the thermogram of CUSO4.5H2O. Limited quantitative analyses have been done e.g. a mixture of the oxalates of Ca, Sr and Ba which decompose at different temperatures. 

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