Evaluation of the reactivity of Hexyl isocyanate with selected stabilizers by 1H NMR spectroscopy

Explosive and propellant formulations, such as gun and rocket propellants, generally consist of several components. Besides fuel and oxidizer, additives like stabilizers, burning-rate moderators, energy suppliers, etc. are used in formulations. Propellants must address many criteria and must have specific properties. To reach these properties interactions between the used chemical components should be analyzed and unintended interaction such as reactions and incompatibilities need to be controlled. This work focuses on the analyzation of possible interactions between different kind of stabilizers and hexyl isocyanate. Isocyanates are used as curing agent for binder matrices. To ensure the intended function of the stabilizers, chemical reactions with free isocyanate should be ruled out. The stabilizers and the isocyanate used in this work are organic substances with protons, therefore ideally suited for investigation by proton nuclear magnetic resonance (1H NMR) spectroscopy. The benchtop NMR spectrometer used is operating at 60 MHz and well suited for in-situ online reaction monitoring. The mixtures of the components were investigated over a specified period of time. The results of the 1H NMR experiments proving possible reactions between various stabilizers and hexyl isocyanate will be presented in this work.