Determination of burn rate affecting elements in composite solid propellant and its ingredients by microwave-induced...

A study of trace metallic elements in solid propellant and its ingredients is important and critical as they affect ballistic properties of solid rocket motor during combustion. In the present study, an attempt is made to develop a rapid, single run and cost-effective analytical technique for the routine and direct analysis of multi elements. Trace level metallic impurities (burn rate affecting elements) present in premix, cured propellant slab and propellant ingredients such as ammonium perchlorate, aluminium, aluminium oxide, dioctyladipate, hydroxy terminated polybutadiene and toluene diisoycanate sourced from different suppliers and propellant slag are determined based on a relatively recent analytical technique, microwave-induced plasma optical emission spectrometry (MIP-OES). Analytical wavelengths are selected based on the sensitivity and interference effects. Precision and accuracy of the developed test procedure for the metallic impurities are demonstrated using replicate analyses of certified calibration standards. The limit of quantification and detection of elements studied is determined. Linear regression coefficients are greater than 0.995. The results obtained demonstrate the potential of MIP-OES technique for the determination of metallic impurities of solid propellant ingredients, pre-mix, cured slab and slag of solid propellants with shortened analysis time which achieved lower detection limits, higher accuracy and better repeatability.