Comparison of the Structure and Thermal Properties of Energetic Binders for Application in Propulsion

Energetic binders, essential components of energetic materials (EMs), act as the main support for the energy and mechanical properties of propulsion. Compared with conventional nitrocellulose (NC), the two binders, nitrated bacterial cellulose (NBC) and nitrate glycerol ether cellulose (NGEC), exhibit promising applications in enhancing the mechanical strength of propulsion due to their inherent physicochemical features. Herein, we present a series of characterizations and methods to study the structures of NC, NBC, and NGEC by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). More importantly, the thermal analysis was performed under four universal heating conditions: programmed, constant temperature, high pressure, and adiabatic. It was found that NBC exhibited higher thermal stability and higher activation energy (Ea) by iso-conversional rate methods of kinetic analysis, including the Friedman, Vyazovkin, Ozawa–Flynn–Wall (OFW), and Kissinger–Akahira–Sunose (KAS) methods. Under high-pressure conditions, the thermal decomposition reaction of NC and NBC was promoted by increased pressure in the range of 0–3 MPa, such as a decreased decomposition temperature, whereas that of NGEC exhibited higher thermal stability. Under adiabatic conditions, it was found that NBC and NGEC presented higher thermal stability than NC, and NBC and NGEC can produce more gases and generate higher pressure in less time. It can be concluded that energetic binders with different structures exert various effects. Hence, the results of this work on the analysis of energetic binders may offer a fundamental theory and data supporting the future applications of NBC and NGEC in propulsion formulas.