Thermal decomposition and kinetic evaluation of composite propellant material catalyzed with nano magnesium oxide

Abstract

Magnesium oxide nano particles have been used to catalyze the composite propellant material based on hydroxy terminated polybutadiene (HTPB) and ammonium perchlorate (AP). Thermal decomposition and the kinetic parameters of catalyzed and non-catalyzed version of the composite solid propellant have been investigated in the present work. X-ray diffraction (XRD) technique and scanning electron microscope (SEM) were used to characterize the MgO nano particles before they were added to the propellant material. The average size of the particles was found to be approximately 20-30 nm. The Arrhenius kinetic parameters of both versions of the propellant were evaluated using Kissinger method. Moreover, three isoconversional methods also have been used for the kinetic analysis of both versions of propellant. These methods include Friedman method, Flynn–Wall–Ozawa method and Kissinger-Akahira-Sunose Method. The comparative analysis of the kinetic parameters as well as the thermal behavior of pure and catalyzed composite solid propellant (CSP) has been done under identical set of reaction conditions. The results indicate that MgO nano particles have an obvious catalytic effect on the thermal decomposition of the composite propellant and consequently, the kinetic parameters also change significantly. The decomposition peak temperature of the propellant decreased nearly 22 o C due to the addition of two percent of MgO as a catalyst. The activation energy of the catalyzed propellant however, increased by 28 kJmol -1 from 127.1 kJmol -1 to 155.4 kJmol -1 . Both the frequency factor and the rate constant increased in the catalyzed version of the propellant material and confirmed that a noticeable catalytic activity has taken place.