Theoretical and Experimental Insights into the Effects of Halogen Composition on the Thermal-Decomposition Details, as well as the Fire-Suppressing Mechanism and Performance of CF3CX=CH2 (X = F, Cl, Br)

The mechanism of thermal decomposition and fire suppression, as well as the fire-extinguishing performance of HFO-1234yf, HCFO-1233xf and 2-BTP agents were investigated by using both the experimental and theoretical methods....

Kinetics and Mechanism of Thermal Decomposition of 1-R-Substituted bis(1,1-Dinitromethyl-3-Nitro- 1,2,4-Triazole-5-yl)

Thermal decomposition kinetics of 1-substituted bis(1,1-dinitromethyl-3-Nitro-1,2,4-triazole- 5-yl) in solution of 1,3-dinitrobenzene is studied with manometric method under isothermal conditions. The limiting stage of thermal decomposition is homolytic break of C-NO2 bond in gem-dinitromethyl group; activation parameters of this stage are calculated. The reactivity of investigated compounds is analyzed. Correlation dependences between logarithm of rate constant, activation energy and steric constant of substituent R are obtained

Products and mechanism of thermal decomposition of chlorpyrifos under inert and oxidative conditions

A flow reactor study and quantum chemical calculations that report the products detected under inert and oxidative conditions from the decomposition of chlorpyrifos.

The mechanism of thermal decomposition of oxidized nickel ore from the Kulikovskoyе deposit in air

The object of the research is oxidized nickel ores from the Kulikovskoye deposit (Southern Urals) – non-conforming nickel-containing raw materials. The work is devoted to the study of chemical and phase composition to substantiate the choice of the method of processing this material in order to obtain valuable inorganic substances in demand in the chemical and metallurgical industries: oxide and (or) magnesium nitrate, iron and nickel containing concentrates, silicon dioxide. The chemical composition of ore demonstrating the feasibility of developing a technology for its complex processing is presented. X-ray phase analysis showed the presence of silicates of the serpentine group (lizardite-1M and lizardite-1T) and the group of spinelids (magnesioferrite) in the oxidized nickel ores of the Kulikovskoye deposit. A literary analysis suggested the presence of other hydrosilicates (antigorite, chrysotile, nimite, talc, revdinskite, clinochlore, etc.). IR spectroscopic analysis was performed to confirm the phase composition. A thermogravimetric analysis was performed, which makes it possible to determine the conditions for the preliminary preparation of ground raw materials. To determine the mechanism of thermal decomposition of ore in air, intermediate products were obtained at temperatures of 600, 700 and 900 °C. According to X-ray diffraction, IR and Raman spectroscopic analyzes, at 600 °C, the removal of OH groups, water molecules and the destruction of the crystal lattices that make up the mineral ore with the formation of oxides (FeO, SiO2, MgO) begins. At 700 °C, island silicates are formed: forsterite Mg2SiO4, larnite Ca2SiO4. At 900 °C, the interaction between silicates continues with the complication of the composition of functional groups. Based on the described properties of minerals and previous work on the hydrometallurgical technology of processing oxidized nickel ores and metal-containing silicate raw materials in order to obtain inorganic substances, nitric acid is proposed as a leaching agent.

Falloff curves and mechanism of thermal decomposition of CF3I in shock waves

The falloff curves of the unimolecular dissociation CF3I (+Ar) → CF3 + I (+Ar) are modelled by combining quantum-chemical characterization of the potential for the reaction, unimolecular rate theory, and experimental information on collisional energy transfer.