In the present study, the effect of four nanocatalysts, namely, purified multi‐walled carbon nanotubes (MWCNTs), MWCNTs functionalized with ionic liquid (MWCNTs‐IL), MWCNTs decorated with iron nanoparticles (Fe‐MWCNTs) and the hybrid Fe‐MWCNTs‐IL on the thermal decomposition of ammonium perchlorate (AP) is highlighted. Firstly, MWCNTs are purified and impregnated under infrared irradiation followed by calcinations to obtain Fe‐MWCNTs. Secondly, a green ionic liquid (IL), based on choline chloride and urea is synthesized and used for the functionalization of MWCNTs and Fe‐MWCNTs to obtain MWCNTs‐IL and Fe‐MWCNTs‐IL, respectively. Subsequently, these nanomaterials at a ratio of 1 wt.% are introduced to AP to assess their catalytic effect using DSC and TG analyses. The obtained results highlight the catalytic effect of the functionalized MWCNTs on the thermal decomposition of AP for which a decrease in decomposition temperature of 10.7, 48.4 and 49.9 °C with an increase in decomposition enthalpy of 56.76, 689.99 and 861.11 J/g for AP supplemented with MWCNTs‐IL, Fe‐MWCNTs and Fe‐MWCNTs‐IL, respectively. Furthermore, the calculation of the kinetic parameters confirms that the best catalytic effect is obtained with the Fe‐MWCNTs‐IL hybrid, revealing the synergistic effect of iron and ionic liquid. This combination allows obtaining the lowest activation energy (∼120 kJ/mol).
Polyurethane (PU) elastomers are largely used in the field of high-energy composites such as composite solid propellants (CSPs) and high-energy polymer-bonded explosives (PBXs) due to their distinguished characteristics. Conventional PU binders are mostly non-energetic materials, and consequently reduce the energy performance significantly. Nitrocellulose (NC), is an energetic polymer widely used as an ingredient in propellants, explosives, fireworks, and gas generators, may be introduced in PUbased compositions to overcome their performance drawback. In this context, PU/NC polymer blends at different mass ratios were prepared in the present work using hydroxyl-terminated polyester prepolymer (Desmophen® 1200) and nitrocellulose (NC) by solution blending process. The physico-chemical structure of the prepared PU/NC polymer composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and density measurements. The thermal decomposition behavior was investigated by differential scanning calorimetry (DSC). Based on the obtained DSC results, the Arrhenius parameters were computed by different isoconversional kinetic approaches, namely, iterative Kissinger-Akahira-Sunose (It-KAS), iterative Flynn-Wall-Ozawa (It-FWO) and Vyazovkin's nonlinear integral method coupled with compensation effect (VYA/CE). Additionally, in order to highlight the influence of the introduction of the NC to the binder composition on the performance of a composite propellant, the theoretical performances, namely, theoretical specific impulse, the adiabatic flame temperature, as well as the ideal exhaust gaseous species were determined based on NASA Lewis Code, Chemical Equilibrium with Application (CEA).
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