Synthesis and properties of poly-isocyanate energetic curing agent

Two tetrafunctional poly-isocyanate energetic curing agents with different molecular weight (EO03-1 and EO03-3) were synthesized via reaction of azido polyether polyol with hexamethylene diisocyanate (HDI). The reaction conditions and post processing steps were investigated. There was an exothermic peak at 252.89 °C referring to the thermal decomposition of azido group in differential scanning calorimetry (DSC) plot of EO03-3 and the glass transition temperature (Tg) was found at -47.13 °C. Thermal decomposition peak of GAP/EO03-3 elastomer was found to be at 254.56 °C and the Tg was found at -45.78 °C. To estimate the potential utility of EO03 in solid rocket propellants, an nitric acid ester, triethylene glycol dinitrate (TEGDN), was added to GAP/EO03-3 system as an energetic plasticizer. It was homogeneous even as the amount of TEGDN was equal to GAP/EO03-3 system and Tg of GAP/EO03-3/50%TEGDN was found at -69.08 °C. Mechanical properties of GAP/EO03 and GAP/EO03-3/chain extender were also studied.