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چکیده
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Thermogravimetry (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) have been used to examine the thermal behavior of Sn+KClO3 ,Sn+KNO3 , and Sn+KClO4 pyrotechnic systems and the results were compared with thermal characteristics of individual constituents. TG curves for tin powder, heated alone in air, showed a relatively slow oxi- dation above 570 8C. From thermal results the decomposition temperatures of KClO3 , KClO4 , and KNO3 , in nitrogen atmos- phere, were measured at 472, 592 and 7008C, respectively. For the Sn+KNO3 pyrotechnic system, the tin oxidation was com- pleted within the range of 480 to 5008C. Replacing KNO3 with KClO4 led to an increase of thermal stability of the pyrotechnic mixture. Among above-mentioned pyrotechnic mixtures, Sn+ KClO3 has the lowest ignition temperature at about 390 8C. The apparent activation energy ( E ), DG# , DH# and DS# of the com- bustion processes were obtained from the DSC experiments. Based on these kinetic data and ignition temperatures, the rela- tive reactivity of these mixtures was found to obey in the follow- ing order: Sn+KClO3 >Sn+KNO3>Sn+KClO4 .
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