The kinetics of the thermal decomposition of the FOX-7 compound at 155°C under semiopen conditions in vessels with a volume of V = 0.8–0.9 cm3 in an air atmosphere and the degree of filling of the vessel with substances m/V = 0.03–0.72 g/cm3 has been studied by the gravimetric method. It is found that at the largest m/V, an induction period is observed in the early stages of the reaction, during which the rate of mass loss of the sample is lower by a factor of ten than the rate of decomposition of FOX-7 in the solid phase. With a decrease in m/V, the induction period is shortened and at m/V = 0.04 g/cm3 it disappears altogether. The appearance of the induction period is due to the fact that nitronic acid, which is the only product of the first stage of decomposition of FOX-7, is well adsorbed on the surface of FOX-7 crystals. At the same time, it almost completely loses its reactivity. As a result, until the end of the adsorption process, the decomposition of FOX-7 proceeds without the formation of gaseous products, and the reaction rate is not fixed by the gravimetric method suitable for studying the kinetics of the reaction at the early stages of decomposition of FOX-7.

The pressure of 1,1-diamino-2,2-dinitroethylene (FOX-7) vapors in the temperature range 140–160°C is determined by the manometric method. The correlation dependence of log Pvap on 1/T is established, which makes it possible to estimate the value of Pvap with satisfactory accuracy in the temperature range of 100–200°C. The kinetics of the reaction in the gas phase are measured at temperatures of 200–230°C and m/V = 10–3–10–4 g/cm3. It is found that under these conditions, in parallel with the usual monomolecular isomerization reaction into the aci-form, a chain process of the direct oxidation of FOX-7 by NO2 proceeds. The consequence of this reaction is a significant decrease in the activation energy observed and the appearance of a dependence of the rate on the experimental conditions. The scheme of the main stages of the chain reaction is presented and the conditions necessary for the manifestation of this reaction are determined.

The content and composition of organic compounds in the bottom sediments of rivers and in soils sampled at the Arctic territory affected by diesel fuel spill were studied by gas chromatograph-mass spectrometry. The composition of diesel fuel was studied. It was found that the groups of compounds characteristic of diesel fuel - n-alkanes, polycyclic aromatic hydrocarbons, alkylbenzenes and trimethylalkylbenzenes, sesquiterpanes, steranes, and hopanes were found mainly in the samples taken downstream at a distance of 0.5-20 km from the pollution source. The highest concentration of identified compounds was detected in bottom sediments and soil sampled at a distance of 20 km from the spill, which is associated with the structural features of the riverbed and bank line. In the samples taken at more remote sites (40-90 km), traces of diesel fuel components were found only in bottom sediments.

The kinetics of the thermal decomposition of diazacyclic derivatives of 1,1-diamino-2,2-dinitroethylene (FOX-7) in a dilute solution of nitrobenzene and in the solid phase are studied by manometric and calorimetric methods. The activation energy data obtained for the solution are used for comparison with quantum chemical calculations and for establishing the relationship between the stability of compounds and the structure of the molecules. The decomposition of these derivatives in solution proceeds according to the same mechanism as the decomposition of FOX-7. Their activation energies decrease with the increasing C=C bond length and are in close agreement with the published data on quantum chemical calculations. By the nature of decomposition in the solid state, these compounds differ significantly from FOX-7. This difference is due to the fact that the condensed products of their decomposition are not solid but liquid compounds.

This paper presents a study of the macrokinetic regularities of combustion and thermal decomposition kinetics of energetic condensed compositions containing high-enthalpy high-nitrogen compounds based on the system of furazan, furoxan, and azepine cycles and poly-2-methyl-5-vinyltetrazole as an active binder. The linear rates of high-temperature transformations (combustion) of compositions with different ratios of components were determined in the nitrogen pressure range 1–6 MPa. The burning rate of compositions of polycyclic compounds and poly-2-methyl-5-vinyltetrazole was found to exceed the burning rate of individual components, with the synergistic effect increasing as the nitrogen pressure in the system is decreased. Kinetic studies of heat release during thermal decomposition of energetic compositions in the temperature range 50–350°C under isothermal and nonisothermal conditions showed that in pressed compositions, there was interaction between the reactants leading to a significant increase in the rate of thermal decomposition of the mixture relative to the rate of decomposition of individual components. The data obtained indicate that one of the reasons for an increase in the burning rate upon mixing of components may be a change in the burning-rate controlling reactions due to the chemical interaction of components of the binary composition.

The kinetic regularities of thermal destruction of polycarbonate films containing Pt, Au, Ag, and Ni nanoparticles were studied. Scanning and transmission electron microscopy, as well as surface plasmon resonance absorption spectra, were used to determine the sizes and shapes of metal nanoparticles in composite films. Nanocomposites were obtained by various methods: by reduction of a precursor in a polycarbonate solution followed by evaporation of the solvent; by deposition on a polymer film surface of nanoparticles formed as a result of diode sputtering of metal in argon plasma or laser ablation in superfluid helium. The rate of thermal decomposition of polycarbonate nanocomposites exceeded the rate of decomposition of the starting polymer. The highest catalytic ability was exhibited by Pt, Au, and Ni nanoparticles in the form of nanowires with diameters of 2–6 nm.

The heat release kinetics in thermally initiated polymerization of 1,4-diethynylbenzene suggested as fuel dispersant in gas generator engines was studied under isothermal conditions in the temperature interval 90–150°С in the melt–vapor two-phase closed system. The enthalpies and entropies of melting, vaporization, and sublimation of 1,4-diethynylbenzene and the kinetics of a decrease in its vapor pressure in the course of polymerization in the melt were determined. Specific features of pressure and temperature variation in the course of propagation of the 1,4-diethynylbenzene combustion front in a cylindrical specimen in a Crawford bomb at the initial pressure of 2 MPa were studied.

The data on the special aspects of the composition of oils located in four areas of the Nenets Autonomous District on the coast of the Barents Sea are presented. Normal and isoprenoid alkanes, naphthalenes, phenanthrenes, fluorenes, biphenyls, sesquiterpanes, steranes, hopanes, dibenzothiophenes, dibenzofurans, retene, and cadalene are identified among petroleum hydrocarbons by means of gas chromatography-mass spectrometry. The concentrations of metalloporphyrins and perylene were determined spectrophotometrically. It is demonstrated that cyclohexane content is much higher than the fraction of acyclic compounds only in oil from the Toboyskoye oil field. The composition of this oil is also characterized by the maximal content of bicyclic terpanes (nordrimans, drimans, and homodrimans). For oils from the Perevoznoye and Toraveyskoye oil fields, the co-presence of vanadyl- and nickel-porphyrins suggests marine conditions of the accumulation of initial organic matter in the absence of bottom water contamination with hydrogen sulphide. Dibenzofurans were identified only in oil from the Toraveyskoye oil field, while the presence of dibenzothiophenes is observed in all the studied oil samples.

The physicomechanical properties and thermal stability of epoxy nanocomposites with TiO2 (anatase – 75%, rutile – 25%) nanoparticles were studied. The TiO2/epoxy polymer (TiO2/EP) nanocomposite films were obtained by curing a pre-sonicated mixture of diane-epoxy resin ED-20, 4,4 '- diaminodiphenylmethane and TiO2 nanoparticles using stepwise technique: 90 °С for 3 hours, then 160 °С for 3 hours. Tensile tests were carried out according to American Society for Testing and Materials ASTM D882-10. The average size of TiO2 nanoparticles and microstructure of the obtained nanocomposites were studied by scanning electron microscopy. It was found that addition of the TiO2 nanoparticles at a concentration above 3 wt.% leads to a decrease in tensile strength at break, apparently due to secondary aggregation processes of nanoparticles. During curing, the average diameter of TiO2 nanoparticles increases from 40 nm to 60 nm. An increase in the elastic modulus, a slight increase in the glass transition temperature, and a decrease in the elongation at break of epoxy nanocomposites at a concentration of TiO2 nanoparticles > 1 wt.% indicate an increase in the rigidity of the epoxy matrix. The nanocomposites obtained were shown to be stable at concentrations of TiO2 nanoparticles up to 5 wt.% and up to 300 °С in vacuum.

Kinetic regularities of the mass loss and heat and-gas release were studied in the thermal decomposition of a solid propellant composed of aluminum, ammonium perchlorate, and a polymer binder. It was shown that, under heating from 40 to 340°C under permanent vacuum conditions, propellant samples decompose without ignition, with the limiting mass loss in the decomposition being 48%. When experiments were performed in air, the propellant formulation decomposes with sharp ignition, with the inflammation temperature (270–287°C) and amount of volatiles released by this instant of time (10–16 wt %) dependent on the heating rate. The kinetic regularities of the mass loss in the decomposition of a solid propellant were described in terms of the polychromatic kinetics model that assumes that the reaction system has ensembles of particles differing in reactivity. The distribution functions of the mass fractions of the propellant by activation energies of decomposition were calculated. The heat release kinetics in the decomposition of a propellant formulation in the temperature range 153–270°C in a closed evacuated system is described by a sum of equations for two parallel reactions: 1st-order reaction with a heat effect Q 1 = 200 ± 5 kJ kg –1 and 1st-order autocatalysis with heat effect Q 2 = 1900 ± 50 kJ kg–1. The rate constants and the activation parameters of the process were determined.

The thermal behavior of Ni(II) chelates with bi-, tri-, and tetradentate azomethine ligands is examined by the methods of thermal analysis (DSC, TGA, and DTA) and kinetic analysis of weight loss. It is shown that the controlled isothermal thermolysis of azomethine complexes of Ni(II) in a self-generated atmosphere is an efficient method for obtaining nickel-containing nanoparticles. Products of thermal conversions of chelate complexes are characterized by the x-ray phase analysis and SEM. The magnetic properties of the nanocomposites obtained are studied.

Upon the dehydration in vacuo , crystals of cobalt and zinc acetylenedicarboxylates (CoADC•2H 2 O and ZnADC•2H 2 O) remain stable only to a certain minimum content of coordination water. Once this content is reached, gaseous decomposition products are abruptly released giving rise to chemically reactive moieties that can initiate the solid-phase polymerization of metal-containing monomers. During the dehydration, stretching and bending bands of carboxyl groups become broader and are shifted, which is indicative of the appearance of a mechanical strain in the crystals. Besides, the removal of one water molecule from the coordination sphere of Zn 2+ leads to a strong shift of the Zn—O stretching band to lower frequencies. At the moment of an extensive release of gaseous products (CO 2 and H 2 O), the deformation gradients increase so that narrow reflections of the crystalline phase are absent in the X-ray powder diffraction pattern. The development of strains in the crystals is facilitated also by the accumulation of free CO 2 molecules in the solid phase, as evidenced by the appearance of the bands at 2338 and 655 cm –1 in the IR spectra. The energy of dehydration of crystalline hydrates estimated by quantum chemical calculations (DFT) is 150—200 kJ mol –1 . This high energy can lead to mechanochemical activation of the destruction of the crystal and coordination structures of CoADC•2H 2 O and ZnADC•2H 2 O upon their dehydration.

Stuctural transformations of 1,1-diamino-2,2-dinitroethene (FOX-7) were investigated in the temperature range 298-513K by means of DSC, TG, isothermal calorimetry, PXRD, IR spectroscopy, and electron microscopy. The data obtained confirm the existence of the high-temperature -FOX-7 polymorph stable above 480K. The heat effect of the transformation is -4.6Jg(-1) (-680Jmol(-1)). Metastable -phase formed in the reverse process has a perfect crystal structure and is stable towards thermal decomposition. Possible mechanisms of sharp deceleration of thermal decomposition of FOX-7 at the 40% conversion are discussed.

The kinetic features of thermal degradation of polycarbonate films containing 0.02–0.13 wt % silver are investigated. The analysis of surface plasmon resonance spectra shows that the composite films contain silver nanoparticles with sizes from 10 to 200 nm. The shapes and sizes of particles are determined via scanning electron microscopy. It is shown that the rates of thermal degradation of the nanocomposites are much higher than the rate of degradation of the initial polycarbonate; the highest catalytic activity is exhibited by spherical silver nanoparticles with sizes below than 40 nm, while particles shaped as bipyramids and having sizes of 100–200 nm are less active catalytically.

The dependences of the temperature and the rate of filtration combustion (FC) of carbon on the main parameters controlling the process were experimentally and theoretically studied. Among these are the fraction of the combustible in the charge, the flow rate of the oxidant, the reactivity of the carbon material, and the level of heat loss via the reactor walls. The transition from the conditions of stationary propagation of the combustion wave to decay occurs critically, upon a minor change in the controlling parameters. The parametric domain of the stationary wave was determined. A simplified unidimensional one-temperature mathematical model was proposed for the description of stationary regimes of FC of solid fuels. The model qualitatively characterizes the dependence of the combustion regime on the main controlling parameters and makes it possible to reveal the critical conditions for the existence of stationary combustion regimes.

For mixtures of carbon materials and an inert filler, dependences of the characteristics of the filtration combustion wave on the gaseous oxidizer supply rate at a fuel content in the mixture of less than 7 wt % were obtained. The existence of a lower concentration limit for a steady-state filtration combustion wave was established. It was demonstrated that at a given intensity of heat loss, the concentration limits are determined by the reactivity of the carbon material and the oxidizer supply rate. At the effective coefficient of heat loss α = 8 W/(m2 K), effective conductivity of mixture material λ = 2 W/(m K), and air supply rate G = 0.1 m/s, the lowest fraction of carbon in the mixture at which combustion is still possible was 4.5 wt % for carbon-carbon composite, 2.5 wt % for activated birch coal, and 2.0 wt % for birch coal, the most reactive kind of carbon.

The mechanism of changes in the molecular-mass distribution of interjunction chains in crosslinked poly(ether urethane) elastomers under deformation has been studied by the method of NMR spectroscopy. In the course of tensile drawing, the molecular-mass distribution changes nonmonotonically. The character of stress-induced changes shows that the breakdown of some bonds is accompanied by formation of new bonds and the development of network fragments with short chains. The strength and thermal stability of poly(ether urethane) elastomers are characterized by extremal dependences on the width of the molecular-mass distribution of interjunction chains. In the case of densely crosslinked and unannealed polyepoxides, mechanical impact (pressure and shear; grinding) is accompanied by changes in their supramolecular structure; in turn, these changes entail an increase in the thermal stability of the samples.