Thermal Effects in  -Irradiated Elastomers

Koptelov, A. A.; Karyazov, S. V.; Milekhin, Yu. M.

doi:10.1023/b:doch.0000039462.75236.fc

Cited by 3 publications

(5 citation statements)

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“…(4) employed by us for describing DSC thermograms is confirmed by the body of experimental data obtained in recent years [7,25,26,[31][32][33]. The nonisothermal methods for the investigation of kinetics, which include the DSC method as well, rest on quite a reliable theoretical foundation [13,[34][35][36].…”

Section: Assessment Of the Critical Parametersmentioning

confidence: 85%

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Special features characteristic of the use of differential scanning calorimetry for the investigation of the kinetics of thermal decomposition of energetic materials

Koptelov¹,

Milyokhin²,

Sadovnichii³

et al. 2008

High Temp

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The results of analysis of mathematical models of "ideal" differential scanning calorimeter are used for determining the experimental conditions which provide for the minimal level of errors of determination of the kinetic constants of exothermal reactions of thermal decomposition of energetic materials under conditions of constant-rate heating of samples and in the isothermal mode. The predicted estimates of admissible values of the basic parameters of models (mass of samples, rate of heating, temperature range of investigations, and so on) are based on the experimental data largely obtained in the investigation of cyclotetramethylenetetranitramine (HMX).

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Section: Assessment Of the Critical Parametersmentioning

confidence: 85%

“…(11) in the form of a series [24] to derive (12) The best (in terms of least squares) approximation of experimental data by expression (12) enables one to successfully determine E and Z for monomolecular reaction by iterations [25].…”

Section: Assessment Of the Critical Parametersmentioning

confidence: 99%

Special features characteristic of the use of differential scanning calorimetry for the investigation of the kinetics of thermal decomposition of energetic materials

Koptelov¹,

Milyokhin²,

Sadovnichii³

et al. 2008

High Temp

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“…Curve 1 is the approximation of DSC data (points 1 ) by Eq. (2); the corresponding kinetic parameters found by an iterative method [10] are given in rows 1 and 2 of Table 1. For Eq.…”

Section: Experimental Data and Discussionmentioning

confidence: 99%

“…Based on these considerations, the authors of some papers concluded that the inverse problem of nonisothermal kinetics is ill-posed in principle [14, p. 186]. The primary grounded reason for such a conclusion is the fact that determining the activation energy by any available method of processing of experimental data [7,10] inevitably includes the operation of repeated differentiation of corrected experimental curves. Owing to the errors in experiment organization and interpretation and mathematical processing of the original curves, the kinetic data for high explosives obtained by different authors are substantially different.…”

Section: Orlov and Mazingmentioning

confidence: 99%

Specific features of thermal decomposition of ammonium perchlorate subjected to γ radiation

Koptelov

Milekhin

2007

Combust Explos Shock Waves

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Results of studying thermal decomposition of ammonium perchlorate (AP) samples in the original form and after irradiation by γ-quanta of 60 Co by methods of differential scanning calorimetry and dynamic thermogravimetry with heating rates b = 0.1-0.3 K/sec are described. Irradiation is performed in air at a temperature of 298 ± 2 K and a dose rate of ≈0.2 Gy/sec in the range of absorbed doses D = 0-150 kGy. Preliminary irradiation is demonstrated to lead to substantial transformations of the pattern of thermal decomposition of ammonium perchlorate in the dynamic regime of heating: the single-stage process of decomposition of non-irradiated samples proceeding at b = 0.107 K/sec in the temperature range of 625 to 743 K is replaced by a multistage process. At D = 150 kGy, exothermal transformations accompanied by noticeable losses of sample mass are observed starting from 473 K. Within experimental errors, the total thermal effect of AP decomposition is found to be independent of the absorbed dose and amounts to −1150 kJ/kg on the average.

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“…Using the sum of the decreasing (in absolute value) terms of series (3) (which generally speaking, diverges), it is possible to achieve satisfactory approximation of the basic relations ω(T ) by iterative methods [8]. Table 1 lists the effective parameters E and Z obtained, the intervals of the relative values of the current mass Table 1.…”

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confidence: 99%

Thermal decomposition of polyester polyurethane and its elastomers exposed to γ-radiation

Milekhin

Koptelov

Sadovnichii

et al. 2006

Combust Explos Shock Waves

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The thermal-decomposition parameters of unplasticized and nitrate ester plasticized polyester polyurethane elastomers with unsaturated carbon-carbon bonds in the initial state and after irradiation with doses of 120-380 kGy (γ-quanta 60 Co) were determined using dynamic thermogravimetry and differential scanning calorimetry.A method for producing condensed energetic systems based on polymers is the use of nitroglycerin and others nitrate esters as plasticizers [1]. The thermodynamic compatibility of nitroglycerin with polyurethanes was studied in [2]. Exposure of such systems to ionizing radiation, which, in particular, can be regarded as a method of modifying their properties without chemicalcomposition changes has been little studied previously.In the present paper, we give results of a study of the thermal decomposition kinetics of the starting and γ-irradiated samples of polyester urethane (PEU) [2], which contains C C bonds, and unplasticized (É-1) and nitrate ester (É-2 andÉ-3) plasticized elastomers based on it. The density of the stating PEU is 1190 kg/m 3 at a temperature of 298 K, and its characteristic viscosity (acetone) is 0.04 m 3 /kg. As plasticizers we used nitroglycerin (É-2) and a mixture of nitrate esters -diethylene glycol dinitrate and triethylene glycol dinitrate (É-3). The mass concentrations of the plasticizers inÉ-2 andÉ-3 elastomers was 75%. The elastomer samples were cured at T = 313 K for 14 days; a nitrile oxide curing agent was used.The thermal decomposition of PEU and elastomers was studied on a Derivatograph thermal analyzer [3] and a DSM-2 differential scanning calorimeter (DSC) [4]. The experiments on the derivatographs were performed at atmospheric pressure in air and in a nitrogen atmosphere in the temperature range T = 293-873 K. The 1 Federal Center for Dual-Use Technologies "Soyuz," Dzerzhinskii 140090; fcdt@monnet.ru.initial mass (m 0 ) of the samples was 50 mg. The limiting errors in measuring the temperature and current mass of the samples were ±3 K and ±1 mg, respectively; the average heating rates of the samples in the decomposition temperature range was 0.21-0.27 K/sec. Experiments on the DSM-2 device were performed with samples of initial mass 1-2 mg in air and in nitrogen using unsealed aluminum crucibles. In most of the experiments, the heating rates were 0.11 and 0.22 K/sec. The sample temperature was determined with the maximum error of ±2 K. The materials studied were irradiated on a γ-facility using 60 Co radiation at T = (300 ± 2) K without access of air. The absorbed dose rate determined using the calorimetric method [5] was (0.20 ± 0.01) Gy/sec. The samples were irradiated to maximum doses of D = 380 kGy (for PEU andÉ-1 elastomer) and D = 120 kGy (forÉ-2 andÉ-3 elastomers). The time interval between the cessation of irradiation and the beginning of the experiments was 0.5-48 h. During this interval, the samples were stored in a sealed container at a temperature of (279 ± 1) K.The PEU studied was exposed to intense radiation cross linking. The beginning of gel...

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Thermal Effects in -Irradiated Elastomers

Cited by 3 publications

References 1 publication

Special features characteristic of the use of differential scanning calorimetry for the investigation of the kinetics of thermal decomposition of energetic materials

Special features characteristic of the use of differential scanning calorimetry for the investigation of the kinetics of thermal decomposition of energetic materials

Specific features of thermal decomposition of ammonium perchlorate subjected to γ radiation

Thermal decomposition of polyester polyurethane and its elastomers exposed to γ-radiation

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