Studies on PBFMO-b-PNMMO alternative block thermoplastic elastomers as potential binders for solid propellants

摘要

An energetic polymer, poly[3,3-bis(2,2,2-trifluoro-ethoxymethyl)oxetane]glycol- block -poly(3-nitratomethyl-3-methyloxetane) (PBFMO- b -PNMMO), was synthesized using poly[3,3-bis(2,2,2-trifluoro-ethoxymethyl)oxetane]glycol (PBFMO) and poly(3-nitratomethyl-3-methyloxetane) (PNMMO) as the raw materials and toluene diisocyanate as the coupling agent via a prepolymer process. The structures of the energetic polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), ~(1) H nuclear magnetic resonance spectrometry ( ~(1) H-NMR), and ~(13) C nuclear magnetic resonance spectrometry ( ~(13) C-NMR). A universal testing machine, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to investigate the mechanical properties and thermal behavior of PBFMO- b -PNMMO. The PBFMO- b -PNMMO-based elastomers exhibited superior mechanical properties (10.54 MPa, 723%) in comparison with PNMMO (6.18 MPa, 635%) and good compatibility with HMX and Al. The glass transition temperature ( T _(g) ) and decomposition temperature ( T _(d) ) were found to be ?20.4 and 220 °C, respectively. The cook-off results indicated that the PBFMO- b -PNMMO/Al compositions could release significantly more heat than the PNMMO/Al compositions. Therefore, PBFMO- b -PNMMO may serve as a promising energetic binder for future solid propellant formulations.