PolyNIMMO-HTPE-polyNIMMO triblock copolymer as a potential energetic binder: Synthesis and characterization

A novel energetic polymer binder was developed through ring opening copolymerization of 3-nitratomethyl-3-methyloxetane (NIMMO) with (HTPE) as a macroinitiator to form tri-block copolymer polyNIMMO-HTPE-polyNIMMO. The structure of tri-block copolymer was confirmed by FTIR, H-1 NMR, C-13 NMR and GPC. In comparison with HTPE, polyNIMMO-HTPE-polyNIMMO has a higher viscosity because of its increased molecular weight with additional -ONO2 as side groups and strengthened intermolecular interaction. The glass transition temperature studies show two glass transition processes in their DSC curves. One signal around - 69 degrees C arises from the HTPE segment, while the other signal around - 30 degrees C is related to the terminal polyNIMMO segments in the tri-block polymers. The TGA-DTG and DSC curves indicate that polyNIMMO-HTPE-polyNIMMO has a good thermal stability and its exothermic decomposition peak is found to be around 220 degrees C. The kinetic parameters and the thermodynamic parameters for the thermal decomposition of polyNIMMO-HTPE-polyNIMMO-IV are obtained from the DSC data by non-isothermal methods proposed by ASTM E698 and FWO. These results demonstrate that tri-block copolymer polyNIMMO-HTPE-polyNIMO might be a potential energetic propellant binder.