FT-i.r. spectra of gaseous products from the combustion of pyrotechnic mixtures containing carbon

Abstract

FT-i.r. transmission spectroscopic studies show that CO 2 is the major gaseous product from the combustion in air, of ternary mixtures containing carbon, whereas the formation of other gaseous products is dependent upon the type of gas used for combustion. The ternary pyrotechnic mixtures of carbon containing KNO 3 produce nitrogen oxides (N 2O and NO) together with CO in appreciable amounts under N 2 atmosphere, whereas in Ar, only small amounts of NO and CO are formed. SO 2 and NO 2 are formed only under O 2 atmosphere in appreciable quantities. The ternary pyrotechnic mixture of carbon containing KClO 4 and S, produces SO 2 as a second major gaseous product after CO 2 together with CO as minor product. Under N 2, it also produces a small amount of N 2O and NO. In O 2, the amount of CO 2 and SO 2 increased further while a decrease in CO occurred. These results show that combustion of KNO 3-derived pyrotechnic mixtures proceed through the formation of nitrogen or nitrogen oxides, whereas in a KClO 4-derived mixture, atomic or molecular oxygen takes part in the combustion reactions.