Inter molecular azide–diisocyanate coupling: new insights for energetic solid propellants

摘要: Hydroxyl terminated azide binders can undergo a spurious reaction with diisocyanates to form tetrazoline-5-one via an inter molecular 1,3-dipolar cycloaddition apart from urethane/allophanate groups which has been overlooked. This serious implications on solid propellants. The computed activation barrier using density functional theory (DFT) for urethane formation is 28.4 kJ mol−1 and that 108.0 mol−1. DFT studies reveal the rate limiting step of between isocyanate. A dual cure was observed in temperature ranges 42–77 °C 78–146 by differential scanning calorimetry (DSC) rheological studies, confirming multiple reactions. Tetrazoline-5-one confirmed Fourier transform infrared spectroscopy (FTIR) state nuclear magnetic resonance (NMR).