Thermal Decomposition of Ammonium Perchlorate in the Presence of Functionalized MWCNTs

In this study, functionalized multi-walled carbon nanotubes (MWCNT-COOH) were used as a nanocatalyst for thermal decomposition of ammonium perchlorate (AP) as an integral part of composite solid propellants (CSPs). Modification of MWCNTs was performed via acid treatment with concentrated aqueous solution of nitric acid, i.e. 7 M. FE-SEM and FT-IR analyses clearly revealed that nitric acid-treated materials under reflux conditions suffered the highest degree of modification and putting carboxylic acid functional groups on the top or even surface. Raman spectra displayed three types of defects in MWCNTs, i.e. D-band: sp³-hybridization of carbons, G-band: sp²-hybridization of carbons and D’-band: impurity on the surface. A composite was prepared by AP and MWCNT-COOH (3% wt.) via solvent-anti-solvent method and catalytic effects of these multi-walled carbon nanotubes were studied on the thermal decomposition behavior of AP by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Results showed that MWCNT-COOH lowered high temperature decomposition by 89°C and this reaction occurred in one step which was complete decomposition.